Heating furnace reversing valve temperature control system based on multi-measuring-point linkage

Abstract

The invention provides a heating furnace reversing valve temperature control system based on multi-measuring-point linkage, and belongs to the technical field of industrial heating furnace combustion control. The three-way valve temperature measuring galvanic couple is arranged at a smoke discharging side outlet of the three-way reversing valve; the nozzle front temperature measuring galvanic couple is arranged between the nozzle front butterfly valve of each burner and the segmented collecting pipe; the smoke exhaust header pipe temperature measuring galvanic couple serves as a primary temperature measuring point, and the three-way valve temperature measuring galvanic couple serves as a secondary temperature measuring point; the nozzle front temperature measuring galvanic couple is a three-level temperature measuring point; temperature data detected by each level of temperature measuring point is transmitted to the programmable logic controller in real time; and the programmable logic controller judges the temperature data based on a preset logic algorithm, generates a corresponding control signal, and sends the control signal to a corresponding valve execution mechanism to realize control of each valve of the system. According to the system, the problems of potential safety hazards and control lag of traditional single-point detection are effectively solved, and the safety and reliability of the combustion system of the industrial heating furnace are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of combustion control of industrial heating furnaces, and in particular to a heating furnace reversing valve temperature control system based on multi-measurement-point linkage. BACKGROUND

[0002] The combustion system of a double regenerative heating furnace usually adopts a segmented centralized reversing technology, which periodically switches a plurality of burners (such as dozens of burners) through a single reversing valve to realize the switching of the air (gas) and flue gas paths and heat recovery. In this system, the burners are usually equipped with electric butterfly valves, and the sealing performance of the valve body is directly affected by the temperature, especially the sealing components on the high-temperature flue gas path, which are prone to failure due to local overheating. The existing technology mainly relies on centralized temperature monitoring of the exhaust gas header and timed reversing control to ensure safe operation of the system, but this method cannot fully cover the temperature abnormality risks of the branch pipes.

[0003] In the existing technology, only a single thermocouple is usually arranged at the exhaust gas header for temperature monitoring, and the timed start and stop of the reversing valve is triggered by the header temperature signal. For local overheating that may occur in the branch pipes (such as the upper / lower burner branch pipes), such as abnormal temperature rise caused by burner coking or regenerator perforation, the existing solution lacks independent detection means and can only be indirectly inferred through the header temperature, which makes it difficult to discover the overheating of the branch pipes in a timely manner. In addition, when the header thermocouple fails, the system will completely lose the temperature feedback capability, and the reversing valve may continue to operate under overheating conditions, thereby causing valve plate sealing failure, gas leakage, and even micro-explosion and other safety hazards.

[0004] The existing technology has the following defects: (1) the single-point temperature measurement blind area problem is prominent, and the local temperature abnormality of the branch pipes cannot be monitored in real time, which causes the valve plate sealing to frequently fail without triggering protection; (2) the system has no redundant detection mechanism when the thermocouple fails, causing safety protection failure; (3) the control logic is lagging, and the timed reversing based on the header temperature cannot adapt to the dynamic temperature changes of the branch pipes, which aggravates the equipment wear and tear. According to statistics, the existing system has 3-5 shutdown accidents caused by local overheating per year, which has high maintenance cost and insufficient safety.

[0005] Therefore, an improved scheme with multi-dimensional temperature monitoring, redundant protection, and intelligent linkage function is needed to solve the above technical bottlenecks. SUMMARY

[0006] Therefore, the present application provides a heating furnace reversing valve temperature control system based on multi-measurement-point linkage, which constructs a heating furnace reversing valve temperature detection system based on multi-thermocouple redundant layout and intelligent linkage control to realize real-time temperature monitoring and safety protection of the regenerative heating furnace reversing valve.

[0007] To this end, the present application provides the following technical solutions:

[0008] A heating furnace reversing valve temperature control system based on multi-measuring point linkage, comprising:

[0009] A flue gas exhaust main temperature measuring thermocouple arranged at the flue gas exhaust main, a three-way valve temperature measuring thermocouple arranged at the flue gas exhaust side outlet of the three-way reversing valve, and a burner front temperature measuring thermocouple arranged between each burner front butterfly valve and the sectional header;

[0010] The flue gas exhaust main temperature measuring thermocouple serves as a first-level temperature measuring point, the three-way valve temperature measuring thermocouple serves as a second-level temperature measuring point, and the burner front temperature measuring thermocouple serves as a third-level temperature measuring point.

[0011] Temperature data detected by each level of temperature measuring point is transmitted to a programmable logic controller in real time; the programmable logic controller performs threshold value judgment on the temperature data based on preset logic, generates a control signal corresponding to the judgment result, sends the control signal to a corresponding valve actuator, and controls each valve of the system.

[0012] Further, the flue gas exhaust main temperature measuring thermocouple is arranged at the tail of the flue gas exhaust main.

[0013] Further, a stainless steel sleeve is arranged outside the temperature measuring thermocouple; the insertion depth of the temperature measuring thermocouple is 1 / 8-1 / 5 of the outer diameter of the pipeline.

[0014] Further, the temperature measuring range of the temperature measuring thermocouple is 0-300℃.

[0015] A heating furnace reversing valve temperature control method based on multi-measuring point linkage realized by a heating furnace reversing valve temperature control system based on multi-measuring point linkage, comprising:

[0016] The flue gas exhaust main temperature measuring thermocouple detects the flue gas temperature in the flue gas exhaust main as a first-level temperature measuring point, the three-way valve temperature measuring thermocouple detects the flue gas temperature at the flue gas exhaust side outlet of the three-way reversing valve as a second-level temperature measuring point, and the burner front temperature measuring thermocouple detects the flue gas temperature in the burner branch as a third-level temperature measuring point.

[0017] Threshold value judgment is performed on the temperature data of each level of temperature measuring point based on preset logic, a control signal corresponding to the judgment result is generated, the control signal is sent to a corresponding valve actuator, and each valve of the system is controlled.

[0018] Further, the threshold value judgment on the temperature data of each level of temperature measuring point based on preset logic, the generation of a control signal corresponding to the judgment result, and the sending of the control signal to a corresponding valve actuator, comprise:

[0019] When the primary temperature measuring point is in normal operation, if the temperature of a level of temperature measuring point exceeds its own early warning value, a corresponding control signal is generated according to the level of the temperature measuring point; if the temperature of two or more levels of temperature measuring points exceeds, a control signal including the following actions is generated: closing the reversing valve, closing the intake side cylinder, closing the exhaust side cylinder and shutting down the main control system of the heating furnace.

[0020] Further, the threshold value judgment on the temperature data of each level of temperature measuring point based on the preset logic to generate a control signal corresponding to the judgment result further comprises:

[0021] When the primary temperature measuring point fails, if the temperature of the secondary temperature measuring point exceeds its own early warning value, a control signal including the following actions is generated: closing the exhaust side cylinder and keeping the current state of the intake side cylinder until the temperature is below the early warning value to restore automatic reversing; if the temperature of the secondary temperature measuring point does not exceed its own early warning value, a corresponding control signal is generated according to whether the temperature of the tertiary temperature measuring point exceeds its own early warning value.

[0022] Further, if the temperature of a level of temperature measuring point exceeds its own early warning value, a corresponding control signal is generated according to the level of the temperature measuring point, which comprises:

[0023] If the temperature of the primary temperature measuring point or the secondary temperature measuring point exceeds its own early warning value, a control signal including the following actions is generated: closing the exhaust side cylinder and keeping the current state of the intake side cylinder until the temperature is below the early warning value to restore automatic reversing;

[0024] If the temperature of the tertiary temperature measuring point exceeds its own early warning value, a control signal including the following actions is generated: closing the pre-butterfly valve corresponding to the tertiary temperature measuring point whose temperature exceeds its own early warning value.

[0025] Further, the generation of a corresponding control signal according to whether the temperature of the tertiary temperature measuring point exceeds its own early warning value comprises:

[0026] When the temperature of a tertiary temperature measuring point exceeds its own early warning value, a control signal is generated to increase the opening degree of the intake side cylinder to a preset value during gas supply, and a control signal is generated to decrease the opening degree of the intake side cylinder to a preset value during exhaust.

[0027] When the temperature of two or more tertiary temperature measuring points exceeds its own early warning value, a control signal including the following actions is generated: closing the reversing valve, closing the intake side cylinder, closing the exhaust side cylinder and shutting down the main control system of the heating furnace.

[0028] When the temperature of the tertiary temperature measuring point does not exceed its own early warning value, an exhaust main pipe temperature measuring thermocouple failure warning is triggered.

[0029] The advantages and positive effects of the present application are:

[0030] The system adopts a multi-measuring-point linkage temperature measuring layout mode: three measuring points are arranged in the reversing valve exhaust main pipe and the upper / lower burner branch pipe to realize three-dimensional monitoring of the temperature field and solve the accuracy limitation of single-point detection in the prior art.

[0031] In the system, the branch thermocouple is installed close to the reversing valve side to eliminate temperature measuring delay caused by pipeline heat dissipation, realize near-valve end temperature measuring optimization, shorten the temperature response time from 15s of the traditional scheme to 2s, and improve the control real-time performance.

[0032] The multi-measuring-point temperature-based hierarchical control strategy of the method solves the local over-temperature missed detection and single-point dependence problem through a four-layer protection mechanism of "single-point over-temperature independent closing - branch over-temperature accurate isolation - exhaust main pipe failure redundant switching - multi-point over-temperature emergency shutdown". BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Figure 1 The figure is a structure schematic diagram of the heating furnace reversing valve temperature control system based on multi-measuring-point linkage of the embodiment of the present application.

[0035] 1, reversing valve; 2, exhaust main pipe; 3, gas inlet pipe; 4, sectional header; 5, gas cylinder on the inlet side; 6, gas cylinder on the exhaust side; 7, upper burner; 8, lower burner; 9, butterfly valve in front of the burner; 10, exhaust main pipe temperature measuring thermocouple; 11, three-way valve temperature measuring thermocouple; 12, temperature measuring thermocouple in front of the burner.

[0036] Figure 2 The figure is a flow chart of the heating furnace reversing valve temperature control method based on multi-measuring-point linkage in the embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0038] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0039] The present invention provides a temperature control system for a reversing valve of a heating furnace based on multi-measuring point linkage. By arranging redundant temperature measuring thermocouples in the exhaust main pipe and the upper / lower burner branch pipes, a multi-measuring point logical linkage control strategy is established to realize real-time monitoring of the temperatures of the exhaust main pipe, the exhaust header, the upper burner pipe and the lower burner pipe, thereby eliminating detection blind spots. When any temperature measuring point exceeds the temperature or the exhaust main pipe measuring point fails, the system automatically triggers a hierarchical protection mechanism to ensure the safe operation of the reversing valve. By comparing and analyzing the temperature data of multiple measuring points, the over-temperature source (abnormal exhaust main pipe / header / branch) can be quickly identified to guide targeted maintenance.

[0040] Combine Figure 1 As shown, this system includes:

[0041] 1. Three-level temperature measurement network:

[0042] First-level temperature measuring point: exhaust main pipe temperature measuring thermocouple, installed at the tail end of the exhaust main pipe, to detect the flue gas temperature in the exhaust main pipe.

[0043] Secondary temperature measurement point: The segmented header temperature measuring thermocouple is installed at the exhaust side outlet of the three-way reversing valve to detect the header flue gas temperature.

[0044] Level 3 temperature measuring point: The nozzle-front temperature measuring couple is installed at the outlet of each nozzle-front butterfly valve to detect the temperature of the branch pipe near the valve end; preferably, the nozzle-front temperature measuring couple is 500mm away from the nozzle-front butterfly valve and is located upstream of the nozzle-front butterfly valve.

[0045] Preferably, the thermocouple model is WRE-230 / E, with a temperature measurement range of 0-300°C and an accuracy of ±1.5°C;

[0046] Preferably, a stainless steel sheath is used to protect each thermocouple, and the insertion depth is 1 / 8 to 1 / 5 of the outer diameter of the pipe to ensure temperature measurement accuracy.

[0047] 2. The programmable logic controller receives temperature signals from various temperature measurement points, performs multi-measurement point logic operations, and generates control signals to be sent to the reversing valve actuator.

[0048] The reversing valve actuator includes: an intake side cylinder, a flue gas side cylinder and a nozzle front butterfly valve; each actuator can be independently controlled.

[0049] In combination Figure 2 A multi-measurement-point linkage-based heating furnace reversing valve temperature control method implemented by a multi-measurement-point linkage-based heating furnace reversing valve temperature control system, comprising:

[0050] S1, detecting the flue gas temperature in the heating furnace by a temperature measuring thermocouple:

[0051] The flue gas temperature in the flue gas main pipe is detected by a temperature measuring thermocouple as a first temperature measuring point, the flue gas temperature at the flue gas side outlet of the three-way valve is detected by a temperature measuring thermocouple as a second temperature measuring point, and the flue gas temperature in the burner branch is detected by a temperature measuring thermocouple as a third temperature measuring point.

[0052] S2, judging the temperature data detected by each temperature measuring point and generating corresponding control signals; sending the control signals to corresponding valve actuators to control the valves in the system:

[0053] 1, when the first temperature measuring point is working normally:

[0054] 1) if the temperature of only one temperature measuring point exceeds its own warning value, generate corresponding control signals according to the level of the temperature measuring point:

[0055] ① if the temperature of the first temperature measuring point or the second temperature measuring point exceeds its own warning value, generate a control signal to close the flue gas side cylinder and keep the current state of the intake side cylinder until the temperature is below the warning value to restore automatic reversing;

[0056] ② if the temperature of the third temperature measuring point exceeds its own warning value, generate a signal to close the corresponding flue gas side cylinder or nozzle front butterfly valve to cut off the flue gas passage of the abnormal burner.

[0057] 2) if the temperature of two or more temperature measuring points exceeds, generate a signal to close the reversing valve, close the intake side cylinder and the flue gas side cylinder, and shut down the main control system of the heating furnace.

[0058] 2, when the first temperature measuring point fails:

[0059] 1) if the temperature of the second temperature measuring point exceeds its own warning value, close the flue gas side cylinder and keep the current state of the intake side cylinder until the temperature is below the warning value to restore automatic reversing.

[0060] 2) if the temperature of the second temperature measuring point does not exceed its own warning value, generate corresponding control signals according to whether the temperature of the third temperature measuring point exceeds its own warning value:

[0061] ① When only one tertiary temperature measuring point temperature exceeds its own early warning value, the control signal for increasing the intake side cylinder opening degree during gas supply and decreasing the intake side cylinder opening degree during exhaust is generated;

[0062] ② When more than two tertiary temperature measuring points exceed their own early warning values, the control signal for increasing the intake side cylinder opening degree during gas supply and decreasing the intake side cylinder opening degree during exhaust is generated;

[0063] ③ When the tertiary temperature measuring point temperature does not exceed its own early warning value, the alarm signal of the exhaust gas pipe temperature measuring couple is generated.

[0064] Preferably, the early warning value of the primary temperature measuring point is 180℃, the early warning value of the secondary temperature measuring point is 200℃, and the early warning value of the tertiary temperature measuring point is 220℃.

[0065] Normal working condition control (primary temperature measuring point temperature <180℃, secondary temperature measuring point temperature <200℃, and tertiary temperature measuring point temperature <220℃)

[0066] The reversing valve is switched according to the timing program, and the temperature of each measuring point is displayed in real time on the HMI interface. Preferably, the timing is 45s.

[0067] Based on S2, four abnormal working condition scenarios can be constructed, including:

[0068] Scenario one: only one level of temperature measuring point is overheated, including:

[0069] The primary temperature measuring point temperature (T1) is ≥180℃ or the secondary temperature measuring point temperature (T2) is ≥200℃ or the tertiary temperature measuring point temperature (T3) is ≥220℃.

[0070] Action: PLC immediately sends a forced shutdown instruction, the exhaust side cylinder is closed within 500ms, and the flue gas passage is cut off; the intake side cylinder remains in the current state to prevent air / gas backflow until the temperature is below the early warning value and automatic reversing is restored;

[0071] Alarm: HMI flashes to display the overheated measuring point position, triggers an audible and visual alarm, and prompts the operator to troubleshoot the overheating cause.

[0072] Scenario two: primary temperature measuring point failure, including: primary temperature measuring point signal anomaly or fluctuation >±10℃ for 10s.

[0073] Redundancy switching: automatically shield the primary temperature measuring point signal and switch to the segmented and branched measuring point priority mode, using the secondary temperature measuring point temperature and the tertiary temperature measuring point temperature as the control basis;

[0074] If the secondary temperature measuring point temperature is overheated, execute scenario one forced shutdown;

[0075] If the tertiary temperature measuring point of a single burner is overheated, increase the intake side cylinder opening degree during gas supply and decrease the intake side cylinder opening degree during exhaust;

[0076] If the secondary temperature measuring point and the tertiary temperature measuring point are normal, maintain the timing reversal, and at the same time, the HMI prompts "flue gas exhaust main thermocouple fault", and the maintenance is carried out at the right moment.

[0077] Scenario three: the temperature of the primary temperature measuring point is less than 180℃, the temperature of the secondary temperature measuring point is greater than or equal to 200℃, or the temperature of the tertiary temperature measuring point is greater than or equal to 220℃.

[0078] Precise isolation: the PLC sends a command to close the corresponding flue gas exhaust side cylinder or the pre-nozzle butterfly valve, cutting off the flue gas passage of the abnormal burner, and at the same time, the reversing valve is out of the automatic control program and becomes an independent unit control (only controlling the reversing action of the non-over-temperature branch);

[0079] Production continuity: the non-over-temperature branch maintains normal combustion, avoiding the shutdown of the whole furnace due to the abnormality of a single burner, and reducing production loss.

[0080] Scenario four: multiple measuring points overheat at the same time, including: the temperature of the primary temperature measuring point is greater than or equal to 180℃ and the temperature of the secondary temperature measuring point is greater than or equal to 200℃, the temperature of the primary temperature measuring point is greater than or equal to 180℃ and the temperature of the tertiary temperature measuring point is greater than or equal to 220℃, or all three measuring points overheat.

[0081] The highest level of protection: immediately cut off all passages of the reversing valve, close the inlet side cylinder and the flue gas exhaust side cylinder at the same time, and trigger the emergency shutdown;

[0082] Linkage response: send a shutdown signal to the heating furnace main control system, cut off the fuel supply, prevent the accident from expanding, and at the same time, record the over-temperature data for post-analysis.

[0083] Embodiment

[0084] In combination Figure 2 In this embodiment, the 60t / h regenerative heating furnace adopts a segmented and centralized reversing mode with single control of burners, and the reversing valve is a double-cylinder two-position three-way valve, which is implemented according to the following flow:

[0085] S1, measuring point arrangement:

[0086] The flue gas exhaust main thermocouple is installed at the tail of the flue gas exhaust main pipeline to detect the flue gas temperature, which is vertically inserted into the flue gas exhaust main pipeline at a distance of 3 meters from the chimney with an insertion depth of 100mm, and the outer diameter of the flue gas exhaust main pipeline is 1620mm;

[0087] The sectional header thermocouple is installed at the flue gas exhaust side outlet of the three-way reversing valve to detect the header flue gas temperature, which is vertically inserted into the flue gas exhaust main pipeline at a distance of 1m from the outlet of the reversing valve with an insertion depth of 80mm, and the outer diameter of the sectional header pipeline is 630mm;

[0088] The pre-burner thermocouple is installed at the outlet of each pre-burner butterfly valve to detect the temperature near the valve end of the branch pipeline, which is vertically inserted into the flue gas exhaust main pipeline at a distance of 500mm from the valve plate and located upstream of the pre-burner butterfly valve with an insertion depth of 60mm, and the outer diameter of the burner pipeline is 377mm;

[0089] S2, system debugging:

[0090] Calibration thermocouple zero, set temperature threshold 180℃, 200℃, 220℃, respectively, import hierarchical control logic program;

[0091] Simulate the following working conditions to verify the function:

[0092] The first three temperature measuring points over temperature (250℃), the first nozzle front butterfly valve is closed within 0.5s, HMI display "the first burner over temperature";

[0093] Second temperature measuring point over temperature (220℃), exhaust side cylinder is closed within 1s, reversing valve is converted to independent control, HMI display "all east reversing over temperature";

[0094] The first temperature measuring point temperature signal interruption: the system automatically switches to the second temperature measuring point, the third temperature measuring point control, and simultaneously alarms "exhaust manifold thermocouple fault";

[0095] Three measuring points are over temperature (220℃): reversing valve is fully closed within 1s, and the heating furnace is synchronously stopped.

[0096] S3, actual scene

[0097] The upper burner regenerator perforation causes the third temperature measuring point to continuously over temperature (255℃), and the first temperature measuring point temperature and the second temperature measuring point are normal (170℃, 190℃)

[0098] Detection stage: the third temperature measuring point continuous detection value is greater than 200℃, and the PLC recognizes it as an effective over temperature signal;

[0099] Control stage:

[0100] Immediately close the upper burner nozzle front butterfly valve to cut off the flue gas passage;

[0101] The reversing valve normally reverses, only controls the remaining burner branch to normally switch, and maintains combustion;

[0102] HMI marks "upper burner pipeline over temperature, nozzle front butterfly valve has been closed", and generates a maintenance work order;

[0103] Maintenance stage: after the operator repairs, manually reset the nozzle front butterfly valve, and the system returns to normal control.

[0104] The application provides a heating furnace reversing valve temperature detection system with innovative temperature measuring layout and intelligent control logic, effectively solves the safety hidden danger and control lag problem of traditional single point detection, significantly improves the safety and reliability of the industrial heating furnace combustion system, and has outstanding industrial application value.

[0105] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A heating furnace reversing valve temperature control system based on multi-measurement point linkage, characterized in that: include: The exhaust main pipe temperature measuring couple is installed in the exhaust main pipe, the three-way valve temperature measuring couple is installed at the exhaust side outlet of the three-way reversing valve, and the burner nozzle temperature measuring couple is installed between the butterfly valve and the segmented header in front of each burner nozzle; The exhaust main pipe temperature measuring couple is used as the primary temperature measuring point, and the three-way valve temperature measuring couple is used as the secondary temperature measuring point; The temperature measuring couple in front of the mouth is used as the third-level temperature measuring point; The temperature data detected by temperature measurement points at each level is transmitted to the programmable logic controller in real time; the programmable logic controller performs threshold judgment on the temperature data based on preset logic, generates a control signal corresponding to the judgment result, and sends the control signal to the corresponding valve actuator to realize the control of each valve in the system.

2. The system according to claim 1, wherein: The total temperature measuring couple of the smoke exhaust main pipe is arranged at the tail end of the smoke exhaust main pipe.

3. The system according to claim 1, wherein: A stainless steel sleeve is provided on the outside of the temperature measuring couple; the insertion depth of the temperature measuring couple is 1 / 8 to 1 / 5 of the outer diameter of the inserted pipe.

4. The system according to claim 1, wherein: The temperature measuring range of the thermocouple is 0-300°C.

5. A method for controlling the temperature of a heating furnace reversing valve based on multi-measurement-point linkage, implemented by the heating furnace reversing valve temperature control system based on multi-measurement-point linkage according to any one of claims 1 to 4, characterized in that: include: The exhaust main pipe temperature measuring couple is used as the first-level temperature measuring point to detect the flue gas temperature in the exhaust main pipe. The three-way valve temperature measuring couple is used as the second-level temperature measuring point to detect the flue gas temperature at the exhaust side outlet of the three-way reversing valve. The nozzle front temperature measuring couple is used as the third-level temperature measuring point to detect the flue gas temperature in the burner branch. Based on the preset logic, the temperature data of each level of temperature measurement point is judged by threshold value, and a control signal corresponding to the judgment result is generated. The control signal is sent to the corresponding valve actuator to realize the control of each valve in the system.

6. The method according to claim 5, characterized in that The method of performing threshold judgment on the temperature data of each level of temperature measurement point based on the preset logic and generating a control signal corresponding to the judgment result includes: When the first-level temperature measuring point is working normally, if the temperature of a temperature measuring point of one level exceeds its own warning value, a corresponding control signal will be generated according to the level of the temperature measuring point; if two or more temperature measuring points exceed the temperature, a control signal including the following actions will be generated: closing the reversing valve, closing the air intake side cylinder, closing the exhaust side cylinder and shutting down the heating furnace main control system.

7. The method according to claim 5, characterized in that The method further comprises: performing threshold judgment on the temperature data of each level of temperature measurement point based on the preset logic and generating a control signal corresponding to the judgment result; When the first-level temperature measuring point fails, if the temperature of the second-level temperature measuring point exceeds its own warning value, a control signal including the following actions is generated: close the exhaust side cylinder and maintain the current state of the intake side cylinder until the temperature is lower than the warning value and automatic reversing is restored; if the temperature of the second-level temperature measuring point does not exceed its own warning value, a corresponding control signal is generated based on whether the temperature of the third-level temperature measuring point exceeds its own warning value.

8. The method according to claim 6, characterized in that If the temperature of a temperature measuring point of a level exceeds its own warning value, a corresponding control signal is generated according to the level of the temperature measuring point, including: If the temperature of the first-level or second-level temperature measuring point exceeds its own warning value, a control signal including the following actions is generated: shut down the exhaust side cylinder and maintain the current state of the intake side cylinder until the temperature falls below the warning value and automatic reversing is resumed; If the temperature of the third-level temperature measuring point exceeds its own warning value, a control signal including the following actions is generated: closing the front-mouth butterfly valve corresponding to the third-level temperature measuring point whose temperature exceeds its own warning value.

9. The method according to claim 7, characterized in that The method of generating a corresponding control signal according to whether the temperature of the third-level temperature measurement point exceeds its own warning value includes: When the temperature of a third-level temperature measurement point exceeds its own warning value, a control signal is generated to increase the opening of the intake side cylinder to the preset value during air supply, and a control signal is generated to decrease the opening of the intake side cylinder to the preset value during smoke exhaust; When the temperature of two or more level 3 temperature measuring points exceeds their own warning value, a control signal including the following actions will be generated: closing the reversing valve, closing the air intake side cylinder, closing the exhaust side cylinder and shutting down the main control system of the heating furnace; When the temperatures of the three-level temperature measurement points do not exceed their own warning values, the exhaust main pipe temperature measurement couple failure warning is triggered.

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