Blast furnace blower front oxygen mixing safety control system and control method

Abstract

The invention discloses a blast furnace blower front oxygen mixing safety control system and a blast furnace blower front oxygen mixing safety control method. The blast furnace blower front oxygen mixing safety control system comprises an air flow path, an oxygen flow path, a nitrogen flow path and a controller, the air flow path comprises an air pipeline, an air filter, an oxygen mixer, an oxygen content transmitter, an air blower and an air blast flow transmitter; the oxygen flow path comprises an oxygen pipeline, an oxygen filter, an oxygen purity transmitter, an oxygen pressure regulating valve, an oxygen pressure transmitter, an oxygen flow regulating valve, an oxygen flow transmitter, an oxygen quick switching valve and an oxygen check valve; the nitrogen flow path comprises a nitrogen pipeline, a nitrogen quick-opening valve and a nitrogen check valve. The oxygen enrichment rate of the blast furnace can be directly controlled, the phenomenon that the oxygen enrichment rate of the blast furnace fluctuates due to blast volume change or oxygen purity change is reduced, and the safety of the blast furnace blower is improved.

Description

Technical Field

[0001] This application belongs to the field of blast furnace blast furnace oxygen mixing technology, and particularly relates to a safety control system and control method for oxygen mixing in front of a blast furnace blower. Background Technology

[0002] Adding a certain amount of high-purity oxygen to the cold blast furnace increases its oxygen concentration, thereby improving the smelting intensity and increasing iron production. However, increasing the oxygen concentration at the blast furnace blower inlet presents at least three problems: 1. Controlling only the oxygen quantity does not directly control the blast furnace oxygen enrichment rate, leading to fluctuations in the oxygen enrichment rate when the blast volume changes; 2. Changes in oxygen purity or pressure cause variations in the pure oxygen flow rate, resulting in large fluctuations in the blast furnace oxygen enrichment rate; 3. Safety issues arise when the oxygen mixing unit malfunctions or the blast furnace blower shuts down. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a safety control system and method for oxygen mixing before the blast furnace blower, which can directly control the oxygen enrichment rate of the blast furnace, reduce the fluctuation of the oxygen enrichment rate of the blast furnace caused by changes in blast volume or oxygen purity, and improve the safety of the blast furnace blower.

[0004] In a first aspect, this application provides a blast furnace blower pre-blown oxygen mixing safety control system, which includes: an air flow path, an oxygen flow path, a nitrogen flow path, and a controller; The airflow path includes an air duct, and an air filter, an oxygen mixer, an oxygen content transmitter, a blower, and a blower flow transmitter connected in series along the airflow direction. The oxygen flow path includes an oxygen pipeline, and an oxygen filter, an oxygen purity transmitter, an oxygen pressure regulating valve, an oxygen pressure transmitter, an oxygen flow regulating valve, an oxygen flow transmitter, an oxygen quick-cut valve, and an oxygen check valve connected in series along the oxygen flow direction. The output end of the oxygen pipeline is connected to the oxygen mixer. The nitrogen flow path includes a nitrogen pipeline, and a nitrogen quick-opening valve and a nitrogen check valve connected in series along the nitrogen flow direction. The output end of the nitrogen pipeline is connected to an air pipeline. The controller is electrically connected to the oxygen content transmitter, the blower flow transmitter, the oxygen purity transmitter, the oxygen pressure regulating valve, the oxygen pressure transmitter, the oxygen flow regulating valve, the oxygen flow transmitter, the oxygen quick-cut valve, and the nitrogen quick-open valve, respectively. The controller is used to control the operation of the oxygen pressure regulating valve, the oxygen flow regulating valve, the oxygen quick-cut valve, and the nitrogen quick-open valve based on the oxygen content information, the blower flow information, and the oxygen purity information.

[0005] The blast furnace blower pre-blown oxygen mixing safety control system of this application utilizes a cascade regulation system composed of an oxygen pressure regulating valve and an oxygen flow regulating valve to achieve more stable oxygen flow regulation. Simultaneously, an oxygen purity transmitter is connected to facilitate flow correction, further stabilizing the pure oxygen flow into the blower. By installing an oxygen content transmitter in conjunction with an oxygen quick-cut valve and a nitrogen quick-open valve, nitrogen is introduced to rapidly dilute the oxygen content within the blast furnace blower, preventing fires and other safety accidents caused by excessively high oxygen concentrations in the mixed gas entering the blower, thereby ensuring the safe operation of the blast furnace blower.

[0006] According to one embodiment of this application, a temperature transmitter is installed on the air duct. Along the air flow direction, the temperature transmitter is located behind the blower, and the temperature transmitter is electrically connected to the controller.

[0007] According to one embodiment of this application, a sampling tube is connected to an air pipeline, and an oxygen content transmitter is installed on the sampling tube.

[0008] According to one embodiment of this application, at least two sampling tubes are provided, and two adjacent sampling tubes are arranged at an angle along the circumference of the air duct. The oxygen content transmitter is provided with at least two corresponding sampling tubes.

[0009] According to one embodiment of this application, an oxygen vent pipe is connected to the oxygen pipeline. Along the direction of oxygen flow, the oxygen vent pipe is located in front of the oxygen filter. An oxygen vent valve is provided on the oxygen vent pipe, and the oxygen vent valve is electrically connected to the controller.

[0010] According to one embodiment of this application, the oxygen flow path further includes an oxygen buffer tank, which is connected to the oxygen pipeline via an oxygen buffer pipe. The oxygen buffer pipe is connected to the portion of the oxygen pipeline located between the oxygen filter and the oxygen purity transmitter. An oxygen buffer tank shut-off valve is provided on the oxygen buffer pipe. The nitrogen flow path also includes a nitrogen buffer tank, which is connected to the nitrogen pipeline via a nitrogen buffer pipe. Along the direction of nitrogen flow, the nitrogen buffer pipe is connected to the part of the nitrogen pipeline located before the nitrogen quick-opening valve, and a nitrogen buffer tank shut-off valve is provided on the nitrogen buffer pipe.

[0011] According to one embodiment of this application, along the oxygen flow direction, a first shut-off valve is provided on the oxygen pipeline at a position before the oxygen filter, and a second shut-off valve is provided at a position after the oxygen check valve; and / or, Along the flow direction of nitrogen, a third shut-off valve is installed on the nitrogen pipeline in front of the nitrogen quick-opening valve, and a fourth shut-off valve is installed in the pipeline behind the nitrogen check valve.

[0012] Secondly, this application provides a safety control method for oxygen mixing before the blast furnace blower, based on any of the technical solutions in the first aspect, wherein the control method includes: Obtain the required oxygen enrichment rate, blast flow rate, oxygen purity, and oxygen content for the blast furnace; The required oxygen flow rate is calculated based on the oxygen enrichment rate required for the blast furnace, real-time blast flow rate, real-time oxygen purity, and real-time oxygen content. The oxygen flow regulating valve and / or oxygen pressure regulating valve are activated according to the oxygen demand flow rate to ensure that the oxygen flow rate meets the oxygen demand flow rate.

[0013] According to the blast furnace blower pre-heater oxygen mixing safety control method of this application, through precise parameter acquisition, scientific algorithm calculation, and closed-loop valve control, the direct control of the blast furnace oxygen enrichment rate is achieved. This fundamentally solves the problem of unstable oxygen enrichment rate caused by changes in blast volume and oxygen purity when only the oxygen quantity is controlled in the existing technology. The introduction of the algorithm enables the oxygen flow rate to be dynamically adjusted in real time according to changes in blast flow rate and oxygen purity, ensuring that the oxygen concentration of the mixed gas always meets the blast furnace production requirements, thereby improving the blast furnace smelting intensity and iron production stability.

[0014] According to one embodiment of this application, after controlling the oxygen flow regulating valve to operate according to the oxygen demand flow rate so that the oxygen flow rate reaches the oxygen demand flow rate, the control method further includes: Obtain real-time oxygen content information; If the real-time oxygen content exceeds the preset threshold, the oxygen quick-cut valve will be closed and the nitrogen quick-open valve will be opened. If the real-time oxygen content information is within the set range, the step of calculating the required oxygen flow rate based on the required oxygen enrichment rate of the blast furnace, the real-time blast flow rate, the real-time oxygen purity information, and the real-time oxygen content information is repeated.

[0015] According to one embodiment of this application, the control method further includes: Obtain the temperature information of the blower outlet; If the temperature exceeds the temperature threshold, the oxygen quick-cut valve will be closed, and the nitrogen quick-open valve will be opened.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1This is a schematic diagram of the structure of the blast furnace blower pre-machine oxygen mixing safety control system provided in the embodiments of this application; Figure 2 This is a schematic diagram of the arrangement structure of the air duct and sampling tube provided in the embodiments of this application; Figure 3 This is a schematic flowchart of the oxygen mixing safety control method before the blast furnace blower provided in the embodiments of this application; Figure 4 This is another schematic flowchart of the blast furnace blower pre-machine oxygen mixing safety control method provided in the embodiments of this application; Figure 5 This is another schematic flowchart of the blast furnace blower pre-machine oxygen mixing safety control method provided in the embodiments of this application; Figure 6 This is another schematic diagram of the process for the safe control of oxygen mixing before the blast furnace blower provided in the embodiments of this application.

[0018] Figure label: 100. Blast Furnace Blower Pre-Oxygen Mixing Safety Control System; 1. Air Filter; 2. Oxygen Mixer; 3. Oxygen Content Transmitter; 4. Blower; 5. Temperature Transmitter; 6. Blower Flow Transmitter; 7. Air Pipeline; 8. Oxygen Vent Valve; 9. First Shut-off Valve; 10. Oxygen Filter; 11. Oxygen Buffer Tank; 12. Oxygen Purity Transmitter; 13. Oxygen Pressure Regulating Valve; 14. Oxygen Pressure Transmitter; 15. Oxygen Flow Regulating Valve; 16. Oxygen Flow Transmitter; 17. Oxygen Quick-Switch Valve; 18. Flame Arrestor; 19. Oxygen Check Valve; 20. Second Shut-off Valve; 21. Oxygen Pipeline; 22. Nitrogen Buffer Tank; 23. Third Shut-off Valve; 24. Nitrogen Quick-Opening Valve; 25. Nitrogen Check Valve; 26. Fourth Shut-off Valve; 27. Nitrogen Pipeline; 28. Sampling Tube. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] The following is for reference. Figures 1-2 This application describes a safety control system for oxygen mixing before the blast furnace blower according to an embodiment of the present application.

[0021] Please see Figure 1 This application provides a blast furnace blower pre-blown oxygen mixing safety control system, which includes an air flow path, an oxygen flow path, a nitrogen flow path, and a controller.

[0022] The airflow path includes an air duct 7, and an air filter 1, an oxygen mixer 2, an oxygen content transmitter 3, a blower 4, and a blower flow transmitter 6 connected in series along the airflow direction on the air duct 7.

[0023] The airflow path is the core channel for air delivery in the system. Air duct 7, as the carrier of air circulation, can be made of common industrial pipe materials such as carbon steel pipe or stainless steel pipe. Its pipe diameter is designed to match the rated air volume of blower 4 to ensure smooth airflow without significant resistance.

[0024] Air filter 1 is connected in series at the beginning of air duct 7. Its main function is to filter dust, particulate matter and other impurities in the air, so as to prevent impurities from entering the subsequent equipment and causing wear or blockage, and to extend the service life of core components such as blower 4 and oxygen mixer 2. Its filtration accuracy can be selected from 2μm to 20μm according to the actual working conditions to meet different cleanliness requirements.

[0025] The oxygen mixer 2 is connected after the air filter 1 and is a key component for mixing air and oxygen. It can be a static mixer, a jet mixer, or other types. It has specially structured guide vanes or jet channels inside, which can quickly and evenly mix the two gases and ensure a consistent oxygen concentration distribution in the mixed gas.

[0026] The oxygen content transmitter 3 is installed on the air duct 7 between the oxygen mixer 2 and the blower 4 to detect the oxygen concentration of the mixed gas in real time. The detection range of the oxygen content transmitter 3 can be 0-30%, providing the controller with a key oxygen content feedback signal. Its detection accuracy should be no less than ±0.1% to ensure accurate and reliable data.

[0027] Blower 4 is the power source for the air flow path, used to pressurize the mixed gas and deliver it to the blast furnace. Its power and pressure boosting parameters are matched according to the smelting requirements of the blast furnace to ensure that the blast furnace's blast pressure and flow requirements are met.

[0028] The blower flow transmitter 6 is installed on the air duct 7 after the blower 4 to monitor the gas flow rate output by the blower 4 in real time, providing basic data for the controller to calculate the oxygen demand flow rate. Its measurement range should cover the rated flow range of the blower 4, and the measurement accuracy should not be less than ±0.5%.

[0029] The oxygen flow path includes an oxygen pipeline, and an oxygen filter 10, an oxygen purity transmitter 12, an oxygen pressure regulating valve 13, an oxygen pressure transmitter 14, an oxygen flow regulating valve 15, an oxygen flow transmitter 16, an oxygen quick-cut valve 17, and an oxygen check valve 19 connected in series along the oxygen flow direction. The output end of the oxygen pipeline is connected to the oxygen mixer 2.

[0030] The oxygen flow path is responsible for delivering high-purity oxygen and precisely controlling its flow rate. Stainless steel pipes can also be used for oxygen pipelines. Considering the oxidizing properties of oxygen, the inner wall of the pipe needs to be degreased to avoid safety hazards caused by grease. The pipe diameter is designed according to the maximum oxygen delivery flow rate.

[0031] Oxygen filter 10 is connected in series at the inlet of the oxygen pipeline to filter impurities and welding slag in the oxygen, preventing impurities from affecting the normal operation of subsequent valves and instruments. Its filtration accuracy is usually selected from 60 to 300 mesh / inch to ensure the cleanliness of the oxygen.

[0032] The oxygen purity transmitter 12 is installed after the oxygen filter 10 to detect the oxygen purity in real time, providing a basis for the controller to correct the oxygen flow rate. Its detection range can cover 70%-100%, and the detection accuracy is not less than ±0.1%.

[0033] The oxygen pressure regulating valve 13 is connected after the oxygen purity transmitter 12. Its main function is to stabilize the pressure in the oxygen pipeline and avoid pressure fluctuations from affecting subsequent flow regulation. Its adjustment range can be set to 20Kpa-30Kpa according to the actual working conditions. It has an automatic pressure stabilization function and a response time of no more than 1 second.

[0034] The oxygen pressure transmitter 14 is installed after the oxygen pressure regulating valve 13 to monitor the oxygen pressure after the regulating valve in real time, and feeds the pressure signal back to the controller to form a pressure closed-loop control to ensure that the oxygen pressure is stable within the set range.

[0035] The oxygen flow regulating valve 15 is connected in series after the oxygen pressure transmitter 14. It is the core actuator for controlling the oxygen flow. It can be a pneumatic regulating valve or the like. Its regulation accuracy is not less than ±1%. It can accurately adjust the opening degree according to the controller's instructions to achieve precise control of the oxygen flow.

[0036] The oxygen flow transmitter 16 is installed after the oxygen flow regulating valve 15 to detect the actual oxygen flow in real time and feed the flow signal back to the controller. It forms a flow closed-loop control with the oxygen flow regulating valve 15 to ensure that the oxygen flow reaches the set value.

[0037] The oxygen quick-cut valve 17 is located after the oxygen flow transmitter 16 and has a quick-cut function. Its action response time is no more than 0.5 seconds. When the system malfunctions, it can quickly close and cut off the oxygen supply to prevent the danger from escalating.

[0038] The oxygen check valve 19 is installed at the output end of the oxygen pipeline, near the connection position of the oxygen mixer 2. Its function is to prevent the mixed gas in the oxygen mixer 2 from flowing back into the oxygen pipeline, thus avoiding safety hazards caused by gas backflow or affecting the normal operation of the oxygen flow path.

[0039] The oxygen pipeline outlet can be connected to the oxygen mixer 2 by flange connection, welding connection, etc. The connection part must be sealed to ensure no leakage. The connection position is selected in the middle or upper part of the oxygen mixer 2 so that the oxygen can be mixed with the air more evenly.

[0040] In some examples, a flame arrester 18 is provided on the oxygen pipeline 21, and the flame arrester 18 is located between the oxygen quick-cut valve 17 and the oxygen check valve 19.

[0041] The nitrogen flow path includes a nitrogen pipeline 27, and a nitrogen quick-opening valve 24 and a nitrogen check valve 25 connected in series along the nitrogen flow direction. The output end of the nitrogen pipeline 27 is connected to the air pipeline 7.

[0042] As a safety protection channel, the nitrogen flow path, nitrogen pipeline 27 can be made of carbon steel or stainless steel, and the pipe diameter is designed according to the maximum dilution flow rate of nitrogen.

[0043] The nitrogen quick-opening valve 24 is connected in series with the nitrogen pipeline 27. It has a rapid opening function with a response time of no more than 0.5 seconds. When the system needs to urgently dilute the oxygen concentration, it can be opened quickly to introduce nitrogen into the air pipeline 7.

[0044] The nitrogen check valve 25 is installed at the output end of the nitrogen pipeline 27 to prevent the mixed gas in the air pipeline 7 from flowing back into the nitrogen pipeline 27, thus avoiding cross-contamination or affecting the normal standby status of the nitrogen system.

[0045] The output end of nitrogen pipe 27 is connected to air pipe 7 between oxygen mixer 2 and blower 4, near the intake of blower 4, to ensure that nitrogen can quickly enter blower 4 and achieve rapid dilution of oxygen concentration. In some examples, the output end of nitrogen pipe 27 can also be directly connected to oxygen mixer 2.

[0046] The controller is electrically connected to the oxygen content transmitter 3, the blower flow transmitter 6, the oxygen purity transmitter 12, the oxygen pressure regulating valve 13, the oxygen pressure transmitter 14, the oxygen flow regulating valve 15, the oxygen flow transmitter 16, the oxygen quick-cut valve 17, and the nitrogen quick-open valve 24, respectively. The controller is used to control the operation of the oxygen pressure regulating valve 13, the oxygen flow regulating valve 15, the oxygen quick-cut valve 17, and the nitrogen quick-open valve 24 based on the oxygen content information, the blower flow information, and the oxygen purity information.

[0047] The controller is the core of the entire system. It can be a commonly used industrial controller such as a PLC or DCS controller, featuring multi-channel analog input / output and digital input / output functions. It can simultaneously receive signals from multiple transmitters and control multiple valves. Shielded cables can be used for electrical connections between the controller and each transmitter and valve. When laying cables, keep them away from power cables to avoid electromagnetic interference and ensure stable signal transmission. Oxygen content transmitter 3, blower flow transmitter 6, oxygen purity transmitter 12, oxygen pressure transmitter 14, and oxygen flow transmitter 16 transmit their detected analog signals (such as 4-20mA current signals) to the controller, which then collects, processes, and calculates these signals. Oxygen pressure regulating valve 13, oxygen flow regulating valve 15, oxygen quick-cut valve 17, and nitrogen quick-open valve 24 receive control signals (current signals or switching signals) output from the controller and execute corresponding regulating or switching actions.

[0048] In actual operation, after the system starts, air enters air filter 1 through air pipe 7, and the filtered clean air flows into oxygen mixer 2. Simultaneously, oxygen enters oxygen filter 10 through oxygen pipe. After the filtered oxygen's purity is detected by oxygen purity transmitter 12, it sequentially passes through oxygen pressure regulating valve 13 for pressure stabilization, oxygen flow regulating valve 15 for flow regulation, and then through oxygen flow transmitter 16 to detect the actual flow rate. Finally, it enters oxygen mixer 2 through oxygen quick-cut valve 17 and oxygen check valve 19, where it is uniformly mixed with the air. The mixed gas, after its oxygen concentration is detected by oxygen content transmitter 3, is pressurized by blower 4, and after its flow rate is detected by blower flow transmitter 6, it is delivered to the blast furnace. The controller collects real-time oxygen content information from oxygen content transmitter 3, blast flow information from blast flow transmitter 6, oxygen purity information from oxygen purity transmitter 12, pressure information from oxygen pressure transmitter 14, and flow information from oxygen flow transmitter 16. Based on the preset blast furnace oxygen enrichment rate, it calculates the required oxygen flow rate using a built-in algorithm, and then controls oxygen pressure regulating valve 13 to stabilize the oxygen pressure and oxygen flow regulating valve 15 to adjust the oxygen flow rate to the calculated value. When the oxygen concentration detected by oxygen content transmitter 3 exceeds the set threshold, the controller immediately sends a control signal to close oxygen quick-cut valve 17 to cut off the oxygen supply, and simultaneously opens nitrogen quick-open valve 24 to introduce nitrogen into air pipeline 7 to quickly dilute the oxygen concentration in the mixed gas and prevent safety accidents caused by excessive oxygen concentration.

[0049] According to the blast furnace blower pre-blower oxygen mixing safety control system of this application, a cascade regulation structure is formed by oxygen pressure regulating valve 13 and oxygen flow regulating valve 15. Oxygen pressure regulating valve 13 first stabilizes the oxygen pressure, and then oxygen flow regulating valve 15 precisely controls the flow rate, effectively avoiding the influence of pressure fluctuations on flow regulation and making oxygen flow regulation more stable. At the same time, oxygen purity transmitter 12 detects oxygen purity in real time, and the controller corrects the oxygen flow rate according to the purity change, ensuring that the pure oxygen flow rate mixed into blower 4 remains stable, solving the problem of large fluctuations in oxygen enrichment rate caused by changes in oxygen purity or pressure in the prior art. By setting oxygen content transmitter 3 to monitor the oxygen concentration of the mixed gas in real time, and forming a linkage protection mechanism with oxygen quick-cut valve 17 and nitrogen quick-open valve 24, when the oxygen concentration exceeds the standard, the oxygen can be quickly cut off and nitrogen can be introduced for dilution, fundamentally avoiding safety accidents such as fires caused by excessive oxygen concentration, and greatly improving the operational safety of blast furnace blower 4. In addition, the controller directly calculates the oxygen flow rate based on the oxygen enrichment rate requirement, blast flow rate and oxygen purity, realizing direct control of the blast furnace oxygen enrichment rate. This solves the problem of oxygen enrichment rate fluctuation caused by changes in blast flow rate when only the oxygen quantity is controlled in the existing technology, ensuring the accurate and stable oxygen enrichment rate during the blast furnace smelting process and improving the smelting intensity and iron production of the blast furnace.

[0050] Please see Figure 1 According to some embodiments of this application, a temperature transmitter 5 may be installed on the air duct. Along the air flow direction, the temperature transmitter 5 is located on the rear side of the blower 4, and the temperature transmitter 5 is electrically connected to the controller.

[0051] Temperature transmitter 5 is a key detection component used for real-time monitoring of the temperature of the gas output from blower 4. Its selection must be adapted to the temperature conditions of the blast furnace blast. Industrial-grade temperature sensors are typically chosen, with a measurement range covering 0℃-400℃ and a detection accuracy of no less than ±0.5℃, ensuring accurate capture of subtle changes in gas temperature. This temperature transmitter 5 is installed in the air pipeline behind blower 4, specifically near the blower 4's outlet and before the blower flow transmitter 6. This installation layout allows for direct detection of the actual temperature of the gas after pressurization by blower 4, while avoiding interference from the blower flow transmitter 6, ensuring the accuracy of the detection data.

[0052] The temperature transmitter 5 can be connected to the air line using either a flange or a threaded connection. During connection, a reliable seal must be ensured to prevent gas leakage from affecting detection accuracy or causing safety hazards. If a flange connection is used, a standard industrial flange with a high-temperature resistant gasket can be selected. If a threaded connection is used, PTFE tape or a sealing gasket should be wrapped around the interface, and the transmitter's probe should be fully inserted into the air line to ensure sufficient contact with the gas, avoiding detection errors caused by incomplete probe contact.

[0053] The temperature transmitter 5 is electrically connected to the controller. The connecting cable is a high-temperature resistant, interference-resistant shielded cable, and the cable laying path is far away from power cables and high-temperature areas to reduce the impact of electromagnetic interference and ambient temperature on signal transmission. The temperature transmitter 5 converts the detected temperature signal into a standard analog signal (such as a 4-20mA current signal) and transmits it to the controller. The controller uses its built-in signal processing module to collect and analyze the temperature data in real time.

[0054] During system operation, temperature transmitter 5 continuously monitors the gas temperature downstream of blower 4 and feeds it back to the controller. When combustion occurs in blower 4 due to locally excessive oxygen concentration, the gas temperature will rise abnormally. At this time, the temperature signal received by the controller will exceed the preset safety threshold. After logical judgment, the controller will immediately trigger a safety protection action, complementing the protection mechanism for excessive oxygen content, further ensuring system safety.

[0055] Please see Figure 1 and Figure 2 According to some embodiments of this application, a sampling tube 28 is connected to the air pipeline, and an oxygen content transmitter 3 is installed on the sampling tube 28.

[0056] Sampling pipe 28 is a branch pipe connected to the air pipeline, used to lead out a portion of the mixed gas for oxygen content transmitter 3 to detect. Its material is consistent with that of the air pipeline; carbon steel or stainless steel can be used to avoid gas contamination or detection errors caused by material differences. The diameter of sampling pipe 28 needs to be designed according to the detection flow requirements of oxygen content transmitter 3. A pipe with a diameter of DN8-DN15 can be selected to ensure sufficient gas flow through the transmitter without significantly affecting the flow and pressure of the main air pipeline.

[0057] The sampling tube 28 is connected to the air pipeline between the oxygen mixer 2 and the blower 4. The mixed gas in this area is thoroughly and uniformly mixed, ensuring that the oxygen concentration of the sampled gas is consistent with that in the main pipeline, thus guaranteeing the representativeness of the test results. The connection can be made by welding or flange connection. Welded connections must ensure a smooth, burr-free interface to avoid localized eddies that could affect gas flow; flange connections must be fitted with sealing gaskets to ensure no gas leakage at the connection point. The installation angle of the sampling tube 28 on the air pipeline can be selected between 30° and 90° with the airflow direction, preferably perpendicular to the air pipeline axis, to facilitate rapid capture of gas samples from different locations within the pipeline and reduce sampling deviation.

[0058] The oxygen content transmitter 3 is installed on the sampling tube 28. The specific installation position should be close to the connection end between the sampling tube 28 and the air pipeline to shorten the gas flow path in the sampling tube 28 and reduce the impact of temperature and pressure changes on the detection results. The connection between the transmitter and the sampling tube 28 can be a threaded interface or a flange interface. The threaded interface is convenient for installation, while the flange interface has better sealing performance. The choice can be made according to the actual working conditions.

[0059] After air and oxygen are mixed in the oxygen mixer 2, the mixture flows to the blower 4 through the air pipeline. Simultaneously, a portion of the mixed gas flows into the oxygen content transmitter 3 through the sampling pipe 28. The oxygen content transmitter 3 has a detection range of 0-30%. It monitors the oxygen concentration of the sampled gas in real time and transmits the detection signal to the controller. The controller combines information such as blower flow rate and oxygen purity to make a comprehensive judgment, thereby controlling the operation of components such as the oxygen pressure regulating valve 13 and the flow regulating valve to ensure a stable oxygen enrichment rate in the system. When the oxygen concentration in the gas in the sampling pipe 28 exceeds the standard, the controller immediately activates the safety protection program, cutting off the oxygen supply and introducing nitrogen for dilution.

[0060] Please see Figure 2 According to some embodiments of this application, at least two sampling tubes 28 may be provided, and two adjacent sampling tubes 28 are arranged at an angle along the circumference of the air duct 7. The oxygen content transmitter 3 is provided with at least two corresponding to the sampling tubes 28.

[0061] The number of sampling tubes 28 is not specifically limited and can be flexibly set according to the diameter of the air duct 7 and the uniformity requirements of the mixed gas. For example, two, three, four, six, or more sampling tubes can be set. When the diameter of the air duct 7 is small (e.g., diameter ≤ 500 mm), two sampling tubes 28 can be set; when the diameter is large (e.g., diameter > 500 mm), three or four sampling tubes 28 can be set to ensure that gas samples from different locations in the duct can be collected comprehensively, avoiding detection deviations caused by uneven gas distribution in the duct.

[0062] Adjacent sampling tubes 28 are set at an angle along the circumference of the air duct 7. The angle should be reasonably distributed according to the number of sampling tubes 28 to achieve uniform coverage of the duct cross-section. If two sampling tubes 28 are set, the included angle between adjacent sampling tubes 28 is preferably 90° or 180°. A 90° included angle can cover the two vertical directions of the duct, and a 180° included angle can collect gas samples from both ends of the duct diameter, both of which can effectively improve the representativeness of the sampling. If three sampling tubes 28 are set, the included angle between adjacent tubes is 120°, and the three sampling tubes 28 are distributed in an equilateral triangle on the circumference of the duct. If four sampling tubes 28 are set, the included angle between adjacent tubes is 90°, and they are distributed in a square. This distribution method can cover the entire cross-section of the duct to the greatest extent and ensure that the collected gas samples can reflect the true oxygen concentration of the mixed gas in the duct.

[0063] All sampling tubes 28 maintain consistent structural specifications, with diameters ranging from DN8 to DN15. Their materials are identical to those of the air duct 7 and individual sampling tubes 28, preventing variations in gas flow patterns due to specification differences and ensuring consistent test results. The connection points of each sampling tube 28 to the air duct 7 are all located at the same or adjacent cross-section between the oxygen mixer 2 and the blower 4. Connections are uniformly made using welding or flange connections to ensure consistent installation conditions for all sampling tubes 28, further guaranteeing the impartiality of the sampling process.

[0064] The number of oxygen content transmitters 3 corresponds one-to-one with the sampling tubes 28, that is, one oxygen content transmitter 3 is installed on each sampling tube 28. All oxygen content transmitters 3 have the same model, specifications and detection accuracy. They are all industrial-grade oxygen content transmitters with a detection accuracy of not less than ±0.1% and a measurement range covering the required oxygen concentration range, so as to avoid deviations in detection data due to differences in transmitter performance.

[0065] All oxygen content transmitters 3 are electrically connected to the controller. The connecting cables are shielded cables of the same specification, and their laying paths are consistent to reduce the impact of external interference on signal transmission. Each oxygen content transmitter 3 independently transmits its detected oxygen concentration signal to the controller. The controller comprehensively processes all detection data, and can analyze it by averaging, medianing, or judging data consistency. For example, the controller calculates the average value of the detection values ​​from all oxygen content transmitters 3, using this average value as the actual oxygen concentration of the mixed gas to improve the accuracy of the detection results. If the detection value of a certain transmitter deviates from the detection values ​​of other transmitters by more than a set threshold (e.g., ±0.5%), the controller can determine that the transmitter may be faulty, issue an alarm signal to remind personnel to perform maintenance, and simultaneously use the detection values ​​of the remaining normal transmitters for calculation to ensure the continuous and stable operation of the system.

[0066] Please see Figure 1 According to some embodiments of this application, an oxygen vent pipe may be connected to the oxygen pipeline 21. Along the oxygen flow direction, the oxygen vent pipe is located in front of the oxygen filter 10. An oxygen vent valve 8 is provided on the oxygen vent pipe, and the oxygen vent valve 8 is electrically connected to the controller.

[0067] The oxygen vent pipe is a branch pipe connected to the oxygen pipeline 21. It is used to release oxygen from the oxygen pipeline 21 under specific operating conditions, preventing excessive pressure or oxygen stagnation that could lead to safety hazards. Its material is the same as the oxygen pipeline 21, made of stainless steel and degreased to suit the oxidizing properties of oxygen and prevent grease or impurities on the inner wall of the pipeline from reacting with oxygen and causing danger. The diameter of the oxygen vent pipe is designed according to the main diameter of the oxygen pipeline 21 and the maximum venting flow rate, and can be set to DN100-DN200 to ensure rapid pressure relief during venting, while avoiding material waste or layout inconvenience caused by excessively large pipe diameters.

[0068] The oxygen vent pipe is connected to the oxygen pipeline 21 upstream of the oxygen filter 10. This location is before the oxygen enters the core regulating stage of the system. Venting will not affect the normal operation of subsequent valves, transmitters, and other components, and it directly releases unfiltered oxygen, avoiding waste of filtered clean oxygen. The connection method is welding or flange connection. Welded joints require flaw detection, while flange connections are equipped with high-pressure oxygen-specific sealing gaskets to ensure no leaks at the connection point, preventing the risk of combustion or explosion caused by oxygen leakage. The outlet end of the oxygen vent pipe must extend to a safe outdoor area or a dedicated venting tower, with the outlet facing upwards to prevent the vented oxygen from directly contacting personnel or flammable materials. A fireproof cap can also be installed at the outlet end to further enhance safety.

[0069] The oxygen vent valve 8 is the core component controlling the on / off state of the oxygen vent pipe. It is an oxygen-specific gate valve or ball valve, with a stainless steel body and a PTFE or metal hard seal structure for the sealing surface, ensuring reliable sealing and no leakage in high-pressure oxygen environments. The oxygen vent valve 8 has remote control functionality and can be pneumatically driven. The pneumatic vent valve has a response time of no more than 0.5 seconds, meeting the rapid action requirements for emergency venting in the system. The nominal pressure of the valve must be higher than the maximum working pressure of the oxygen pipeline 21; a P-type valve can be selected. N6 The above-mentioned oxygen valves are suitable for oxygen delivery under pressure conditions.

[0070] During normal operation, the oxygen vent valve 8 remains closed, and oxygen flows normally through the oxygen pipeline 21 to the oxygen filter 10 for subsequent regulation. When abnormal conditions occur in the system, such as the pressure in the oxygen pipeline 21 exceeding a set threshold (determined by the controller in conjunction with the pressure transmitter signal), system shutdown requiring the venting of oxygen from the pipeline, or oxygen purity not meeting requirements requiring discharge, the controller immediately sends a control signal to open the oxygen vent valve 8. At this time, the oxygen in the oxygen pipeline 21 is quickly released to a safe area through the oxygen vent pipe. After the pressure in the pipeline drops to a safe range or the oxygen is vented, the controller sends a signal to close the oxygen vent valve 8. For example, when the oxygen pressure transmitter 14 detects that the pressure exceeds the preset safe pressure limit, the controller simultaneously controls the oxygen pressure regulating valve 13 to close and the oxygen vent valve 8 to open, providing dual protection for rapid pressure relief. When the system shuts down, the controller closes the oxygen quick-cut valve 17 and then opens the oxygen vent valve 8 to vent any residual oxygen in the pipeline, preventing excessively high oxygen concentration in the pipeline during the next startup.

[0071] Please see Figure 1According to some embodiments of this application, the oxygen flow path further includes an oxygen buffer tank 11, which is connected to the oxygen pipeline 21 via an oxygen buffer pipe. The oxygen buffer pipe is connected to the portion of the oxygen pipeline 21 located between the oxygen filter 10 and the oxygen purity transmitter 12. An oxygen buffer tank shut-off valve is provided on the oxygen buffer pipe.

[0072] Oxygen buffer tank 11 is an energy storage component in the oxygen flow path used to stabilize pressure and balance flow. It adopts a cylindrical pressure vessel structure, is made of stainless steel, and has a degreased inner wall to adapt to the oxidizing properties of oxygen and prevent safety hazards caused by impurities or grease. Its volume is designed according to the maximum flow rate and pressure fluctuation range of the oxygen pipeline, and can be set from 25m³ to 100m³ to ensure effective absorption of pressure pulsations and stabilize the pressure of subsequent pipelines. The top of oxygen buffer tank 11 is equipped with a pressure gauge and a safety valve. The pressure gauge is used to monitor the pressure inside the tank in real time, and the safety valve's set pressure is higher than the system's normal operating pressure but lower than the pipeline design pressure to prevent overpressure and potential hazards.

[0073] The oxygen buffer pipeline is a branch pipeline connecting the oxygen buffer tank 11 and the oxygen pipeline 21. It is made of the same material as both the oxygen pipeline 21 and the oxygen buffer tank 11—stainless steel with a degreasing treatment. The pipe diameter is designed according to the charging and discharging flow rate of the oxygen buffer tank 11. This pipeline connects to the section of the oxygen pipeline 21 located between the oxygen filter 10 and the oxygen purity transmitter 12. The oxygen at this location has already been filtered and purified, preventing impurities from entering the buffer tank and causing internal contamination. It also stabilizes the pressure before oxygen purity testing, ensuring accurate oxygen purity data. The connection method uses a flange connection with a high-pressure oxygen-resistant sealing gasket. The connection point must be tested for airtightness to ensure no oxygen leakage.

[0074] The oxygen buffer tank shut-off valve is installed on the oxygen buffer pipeline to control the connection and disconnection between the oxygen buffer tank 11 and the oxygen pipeline 21. An oxygen-specific shut-off valve or gate valve is selected, with a stainless steel body and a metal hard seal or PTFE seal to ensure reliable sealing under high-pressure oxygen conditions. The valve can be manually or electrically driven. The electric oxygen buffer tank shut-off valve is electrically connected to the controller for easy automatic control. Its nominal pressure is matched to that of the oxygen pipeline 21 to meet the system pressure requirements.

[0075] The nitrogen flow path also includes a nitrogen buffer tank 22, which is connected to the nitrogen pipeline 27 via a nitrogen buffer pipe. Along the direction of nitrogen flow, the nitrogen buffer pipe is connected to the part of the nitrogen pipeline 27 located in front of the nitrogen quick-opening valve 24. A nitrogen buffer tank shut-off valve is provided on the nitrogen buffer pipe.

[0076] Nitrogen buffer tank 22 is an energy storage component in the nitrogen flow path used to store nitrogen and ensure emergency supply. It adopts a cylindrical pressure vessel structure, made of carbon steel or stainless steel, and its volume is designed according to the amount of nitrogen required for emergency dilution, typically ranging from 10m³ to 50m³. This ensures that sufficient nitrogen can be quickly released in emergencies to achieve rapid dilution of oxygen concentration. The top of nitrogen buffer tank 22 is also equipped with a pressure gauge and a safety valve. The pressure gauge monitors the internal pressure in real time, and the safety valve prevents overpressure and ensures equipment safety.

[0077] The nitrogen buffer pipeline is a branch pipeline connecting the nitrogen buffer tank 22 and the nitrogen pipeline 27. It is made of the same material as the nitrogen pipeline 27 and the nitrogen buffer tank 22, namely carbon steel or stainless steel. The pipe diameter is designed according to the charging / discharging flow rate of the nitrogen buffer tank 22 and emergency supply requirements, and can be set to DN100-DN200. Along the nitrogen flow direction, this pipeline connects to the section of the nitrogen pipeline 27 located before the nitrogen quick-opening valve 24, ensuring that the nitrogen in the nitrogen buffer tank 22 can be directly delivered to the front end of the nitrogen quick-opening valve 24, quickly entering the main pipeline when the valve opens, avoiding an excessively long delivery path that would affect the response speed. The connection method uses a flange connection with a high-pressure resistant sealing gasket to ensure a reliable seal at the connection and prevent nitrogen leakage.

[0078] The nitrogen buffer tank shut-off valve is installed on the nitrogen buffer pipeline to control the flow between the nitrogen buffer tank 22 and the nitrogen pipeline 27. A nitrogen-specific shut-off valve is selected, with a valve body made of carbon steel or stainless steel, ensuring good sealing performance. The nominal pressure is matched to the nitrogen pipeline 27, typically PN1.0MPa-PN2.5MPa. The valve can be manually or electrically driven. The electric nitrogen buffer tank shut-off valve is electrically connected to the controller and can automatically start and stop charging and discharging according to the system pressure, ensuring that the buffer tank always maintains a sufficient nitrogen reserve.

[0079] In the oxygen flow path, during normal operation, the oxygen buffer tank shut-off valve remains open. A portion of the oxygen filtered by the oxygen filter 10 flows into the oxygen buffer tank 11, replenishing the tank pressure to the system's operating pressure range. When pressure fluctuations occur in the oxygen pipeline 21, the oxygen buffer tank 11 balances the pressure by charging and discharging. When the pressure rises, it absorbs some oxygen; when the pressure decreases, it releases the stored oxygen, thereby stabilizing the pressure within the oxygen pipeline 21. This provides a stable pressure environment for subsequent oxygen purity testing and flow regulation, preventing pressure fluctuations from affecting testing accuracy and regulation effectiveness.

[0080] In the nitrogen flow path, during normal operation, the nitrogen buffer tank shut-off valve remains open, and nitrogen from nitrogen pipeline 27 continuously fills the nitrogen buffer tank 22, maintaining a preset pressure (0.6 MPa-0.8 MPa) to ensure sufficient nitrogen is stored in the buffer tank. In emergency situations such as excessive oxygen concentration, the controller sends a signal to open the nitrogen quick-opening valve 24. At this time, the high-pressure nitrogen stored in the nitrogen buffer tank 22 can be quickly transported through nitrogen pipeline 27 to air pipeline 7, mixing with the mixed gas in the main pipeline to rapidly dilute the oxygen concentration. Compared to relying solely on real-time delivery through nitrogen pipeline 27, this significantly increases the nitrogen supply speed and quantity, ensuring that the oxygen concentration is reduced to a safe range within a short time.

[0081] When the system is shut down or under maintenance, the oxygen buffer tank shut-off valve and the nitrogen buffer tank shut-off valve can be closed to isolate the buffer tanks from the main pipeline. This facilitates separate maintenance of the buffer tanks and prevents gas from flowing back into the buffer tanks from the main pipeline, ensuring maintenance safety. Furthermore, when the electric buffer valve is linked to the controller, the controller can automatically control the valve opening and closing based on the feedback signal from the buffer tank pressure gauge, maintaining stable pressure inside the tank without manual intervention, thus improving the system's automation level.

[0082] Please see Figure 1 According to some embodiments of this application, along the oxygen flow direction, a first shut-off valve 9 is provided on the oxygen pipeline 21 at the position in front of the oxygen filter 10, and a second shut-off valve 20 is provided at the position behind the oxygen check valve 19.

[0083] The first shut-off valve 9 is located on the oxygen pipeline 21, upstream of the oxygen filter 10. It is the on / off control component at the front end of the oxygen flow path, used to isolate the oxygen source from subsequent systems. Its valve body is made of stainless steel and has undergone degreasing treatment to adapt to the oxidizing properties of oxygen, preventing safety hazards caused by grease or impurities. The sealing surface uses a metal hard seal or a PTFE seal structure to ensure no leakage under high-pressure oxygen conditions. The nominal pressure of the first shut-off valve 9 matches that of the oxygen pipeline 21, and its nominal diameter is consistent with the main diameter of the oxygen pipeline 21, ensuring no significant resistance during oxygen delivery. Its actuation method can be manual, electric, or pneumatic. The electrically or pneumatically driven first shut-off valve 9 can be electrically connected to a controller for remote control.

[0084] The second shut-off valve 20 is installed on the oxygen pipeline 21, behind the oxygen check valve 19, near the connection point between the oxygen pipeline and the oxygen mixer 2. It isolates the end of the oxygen flow path from the oxygen mixer 2. Its material, sealing structure, nominal pressure, and diameter are consistent with the first shut-off valve 9 to ensure compatibility and operational stability with the oxygen pipeline 21. The installation position of the second shut-off valve 20 must avoid the operating area of ​​the oxygen check valve 19 to prevent interference with its normal operation. It also facilitates quick disconnection of the oxygen pipeline from the oxygen mixer 2 during maintenance to prevent backflow of the mixed gas.

[0085] Both the first shut-off valve 9 and the second shut-off valve 20 are connected to the oxygen pipeline 21 via flanges, fitted with high-pressure oxygen-specific sealing gaskets. The connections must be tested for airtightness to ensure no oxygen leakage. Along the oxygen flow direction, the pipeline length between the first shut-off valve 9 and the oxygen filter 10, and between the second shut-off valve 20 and the oxygen check valve 19, must allow for maintenance space, typically no less than three times the nominal diameter of the valves, to facilitate valve disassembly and maintenance.

[0086] Along the direction of nitrogen flow, a third shut-off valve 23 is provided on the nitrogen pipeline 27 in front of the nitrogen quick-opening valve 24, and a fourth shut-off valve 26 is provided in the nitrogen check valve 25.

[0087] The third shut-off valve 23 is located on the nitrogen pipeline 27, upstream of the nitrogen quick-opening valve 24. It isolates the nitrogen source from the nitrogen quick-opening valve 24. Its material can be carbon steel or stainless steel, suitable for the inert nature of nitrogen. A standard industrial seal is sufficient for the sealing structure. The nominal pressure matches that of the nitrogen pipeline 27, typically PN1.0MPa-PN2.5MPa, and the nominal diameter matches the main diameter of the nitrogen pipeline 27. The third shut-off valve 23 can be driven manually, electrically, or pneumatically, forming a tiered control system with the nitrogen quick-opening valve 24 to ensure the controllability of the nitrogen supply.

[0088] The fourth shut-off valve 26 is installed on the nitrogen pipeline 27, behind the nitrogen check valve 25, near the connection point between the nitrogen pipeline 27 and the air pipeline 7, to isolate the end of the nitrogen flow path from the air pipeline 7. Its material, sealing structure, nominal pressure, and diameter are the same as the third shut-off valve 23. During installation, it must maintain a reasonable distance from the nitrogen check valve 25 to avoid interfering with the check valve's reverse shut-off function, and to ensure that the connection between the nitrogen pipeline 27 and the air pipeline 7 can be quickly cut off during maintenance.

[0089] The third shut-off valve 23 and the fourth shut-off valve 26 are also connected to the nitrogen pipeline 27 via flanges, equipped with high-pressure resistant sealing gaskets. A leak test must be performed at the connection to prevent nitrogen leakage from affecting the buffering effect or causing waste. Sufficient maintenance and operating space must be reserved along the nitrogen flow direction between the third shut-off valve 23 and the nitrogen quick-opening valve 24, and between the fourth shut-off valve 26 and the nitrogen check valve 25, to facilitate future maintenance operations.

[0090] Under normal operating conditions, the first shut-off valve 9, the second shut-off valve 20 (if set), the third shut-off valve 23, and the fourth shut-off valve 26 (if set) are all kept fully open, which does not affect the normal flow of oxygen and nitrogen and ensures that the system operates stably according to the preset program.

[0091] When the system requires partial maintenance, the corresponding shut-off valves can be closed to achieve zone isolation. For example, when it is necessary to maintain intermediate components of the oxygen flow path such as the oxygen filter 10 and the pressure regulating valve, the first shut-off valve 9 and the second shut-off valve 20 are closed to cut off the passage between the oxygen source and the oxygen mixer 2. At the same time, the residual oxygen in the pipeline is released through the oxygen vent valve 8 (if installed), so that the maintenance area is in a depressurized state to avoid safety accidents caused by oxygen leakage. When it is necessary to maintain the nitrogen quick-opening valve 24, the third shut-off valve 23 and the fourth shut-off valve 26 are closed to isolate the nitrogen source from the air pipeline 7 to ensure the safety of the maintenance process.

[0092] If a system malfunction requires emergency isolation of a pipeline section, the shut-off valves can quickly close. For example, if the oxygen check valve 19 fails, closing the second shut-off valve 20 can prevent a large amount of mixed gas from flowing back into the oxygen pipeline; if the nitrogen check valve 25 fails, closing the fourth shut-off valve 26 can prevent gas in the air pipeline 7 from entering the nitrogen pipeline 27 and causing contamination. Furthermore, manually operated shut-off valves can serve as a backup control for electric valves. When an electric valve fails, the pipeline can be switched on or off manually, enhancing the system's redundancy protection capabilities.

[0093] The shut-off valve enables the system to achieve zone isolation and precise maintenance, avoiding the need for a complete shutdown during maintenance of traditional systems. This improves the system's maintenance convenience and operational continuity. At the same time, through multi-stage shut-off protection, it further reduces safety risks such as gas leakage and backflow, enhancing the reliability and safety of the entire oxygen mixing safety control system.

[0094] Based on the same concept, please refer to Figure 3 and combined Figure 6 This application also provides a method for safe control of oxygen mixing before the blast furnace blower, and a safety control system for oxygen mixing before the blast furnace blower based on any of the above technical solutions.

[0095] The control method includes steps 210, 220 and 230.

[0096] Step 210: Obtain the required oxygen enrichment rate, blast flow rate, oxygen purity, and oxygen content for the blast furnace.

[0097] In step 210, the core task is to collect the basic parameters required by the control logic, providing data support for subsequent flow calculations and valve control. Among these, the required oxygen enrichment rate for the blast furnace is a core parameter preset based on production needs such as the blast furnace's smelting intensity and iron production targets. This parameter is input by staff through the controller's human-machine interface, and the input range can be set from 0.5% to 6% according to the actual operating conditions of the blast furnace. The controller stores this parameter as a fixed reference value, which can be modified at any time through the interface if production needs change.

[0098] The blower flow rate information can be acquired in real time by the blower flow rate transmitter 6 in the air flow path. This transmitter continuously monitors the flow rate of the mixed gas output by the blower 4, converts the flow rate signal into a 4-20mA standard analog signal and transmits it to the controller. The controller receives and analyzes the signal through the signal acquisition module to obtain real-time blower flow rate data (unit: Nm³ / h). The acquisition frequency is set to 2Hz-10Hz to ensure that the dynamic changes in flow rate can be captured.

[0099] Oxygen purity information can be detected in real time by the oxygen purity transmitter 12 in the oxygen flow path. This transmitter monitors the purity of oxygen after it has been filtered by the oxygen filter 10, and converts the detection result into a standard analog signal and transmits it to the controller. The controller then analyzes the signal to obtain real-time oxygen purity data (unit: %). The acquisition frequency is consistent with the blower flow rate information to ensure parameter synchronization. The effective range of oxygen purity data is 70%-100%. If the detected value exceeds this range, the controller will issue a purity abnormality alarm.

[0100] Oxygen content information can be collected by oxygen content transmitter 3. If there are multiple oxygen content transmitters 3, the controller will receive the real-time detection signals of all transmitters and process them by taking the average value, removing outliers and taking the effective average value to obtain the final real-time oxygen content data (unit: %). This data reflects the actual oxygen concentration of the gas after mixing in oxygen mixer 2. The acquisition frequency is 2Hz-10Hz, which is consistent with the acquisition rhythm of other parameters.

[0101] All parameters are transmitted via shielded cables. The controller has a built-in signal filtering module that performs noise reduction on the received analog signals, eliminating abnormal fluctuations caused by electromagnetic interference, equipment vibration, etc., to ensure that the acquired information is true, stable, and reliable, providing an accurate data foundation for subsequent calculations.

[0102] Step 220: Calculate the required oxygen flow rate based on the required oxygen enrichment rate of the blast furnace, real-time blast flow rate, real-time oxygen purity, and real-time oxygen content.

[0103] In step 220, the controller calculates the target oxygen flow rate that meets the oxygen enrichment requirements of the blast furnace based on the parameters obtained in step 210 through a preset mathematical algorithm. The core design of this algorithm is to eliminate the influence of oxygen purity fluctuations and blast flow rate changes on the oxygen enrichment rate, so as to achieve direct and accurate control of the oxygen enrichment rate.

[0104] The specific algorithm formula is as follows: X=(A×B) / (C-20.9%).

[0105] Where: X is the oxygen demand flow rate (unit: Nm³ / h), which is the target value of the oxygen flow rate to be delivered to the oxygen mixer 2 through the oxygen flow path; A is the required oxygen enrichment rate of the blast furnace (unit: %), which is the percentage of additional oxygen concentration in the preset mixed gas. For example, if the preset oxygen enrichment rate A=2%, it means that the oxygen concentration of the mixed gas needs to be increased by 2% based on the basic oxygen concentration of air (20.9%); B is the real-time blower flow rate (unit: Nm³ / h), which is the mixed gas flow rate output by the blower 4 detected by the blower flow rate transmitter 6; C is the real-time oxygen purity (unit: %), which is the purity of oxygen in the oxygen flow path detected by the oxygen purity transmitter 12; 20.9% is the standard oxygen concentration (constant) of air, which is a general reference value for the oxygen content of air in industrial scenarios.

[0106] The additional pure oxygen in the gas mixture (provided by oxygen) is equal to the product of the blast flow rate and the oxygen enrichment rate. The amount of pure oxygen provided by the oxygen is equal to the product of the oxygen flow rate and the portion of oxygen purity exceeding the air oxygen concentration. This balance is used to deduce the required oxygen flow rate X. For example, when the required oxygen enrichment rate for the blast furnace is A=2%, the real-time blast flow rate is B=8000 Nm³ / min, and the real-time oxygen purity is C=85%, substituting these values ​​into the formula yields X=(2%×8000) / (85%-20.9%)≈249.6 Nm³ / min. This means the oxygen flow rate needs to be stabilized at 249.6 Nm³ / min to ensure the oxygen concentration in the gas mixture meets the preset oxygen enrichment rate requirement.

[0107] Step 230: Control the oxygen flow regulating valve 15 and / or the oxygen pressure regulating valve 13 to operate according to the oxygen demand flow rate so that the oxygen flow rate reaches the oxygen demand flow rate.

[0108] In step 230, the controller can send control commands to the oxygen flow regulating valve 15 and / or the oxygen pressure regulating valve 13 based on the oxygen demand flow rate X calculated in step 220, and adjust the oxygen flow rate through valve action to achieve closed-loop control.

[0109] The control logic has two core modes, selectable based on system configuration and operating conditions: The first mode is a cascade control mode, which simultaneously controls the oxygen pressure regulating valve 13 and the oxygen flow regulating valve 15. The controller first converts the oxygen demand flow rate X into a target opening signal for the oxygen flow regulating valve 15. Simultaneously, based on real-time pressure data from the oxygen pressure transmitter 14, it sends a pressure stabilization command to the oxygen pressure regulating valve 13, ensuring the pressure in the oxygen pipeline remains stable within a preset range (e.g., 20KPa-30KPa). After the oxygen flow regulating valve 15 operates according to the target opening signal, the oxygen flow transmitter 16 detects the actual oxygen flow rate in real time and feeds it back to the controller. The controller calculates the deviation between the actual flow rate and X. If the deviation exceeds ±1%, it fine-tunes the opening of the oxygen flow regulating valve 15 until the actual flow rate matches X. During this process, the oxygen pressure regulating valve 13 continuously stabilizes the pressure, preventing pressure fluctuations from causing lag or overshoot in flow regulation, ensuring the stability and rapid response of flow regulation.

[0110] The second mode is a single flow control mode, which only controls the oxygen flow regulating valve 15. This mode is suitable for scenarios where the oxygen source pressure is relatively stable. The controller directly sends an opening command to the oxygen flow regulating valve 15 based on the oxygen demand flow rate X, and performs closed-loop regulation through real-time feedback from the oxygen flow transmitter 16 until the actual flow rate reaches X. If pressure fluctuations occur during the process, causing excessive flow deviation, the controller will automatically switch to cascade control mode, activating the oxygen pressure regulating valve 13 to participate in pressure stabilization and ensure flow control accuracy.

[0111] In some examples, the response speed of valve control can be optimized according to system operating conditions. When the deviation between the oxygen demand flow rate X and the current actual flow rate is large (e.g., deviation > 5%), the controller controls the valve to act quickly (opening change rate of 5%-10% / second) to shorten the adjustment time. When the deviation is small (e.g., deviation ≤ 1%), the controller controls the valve to make slow fine adjustments (opening change rate of 0.5%-1% / second) to avoid drastic fluctuations in flow rate, ensure stable oxygen concentration in the mixed gas, and thus ensure the continuity of blast furnace smelting conditions.

[0112] The blast furnace blower pre-blower oxygen mixing safety control method provided in this application embodiment achieves direct control of the blast furnace oxygen enrichment rate through precise parameter acquisition, scientific algorithm calculation, and closed-loop valve control. This fundamentally solves the problem in existing technologies where controlling only the oxygen quantity leads to unstable oxygen enrichment rates due to variations in blast volume and oxygen purity. The introduction of the algorithm enables the oxygen flow rate to be dynamically adjusted in real time to follow changes in blast flow rate and oxygen purity, ensuring that the oxygen concentration of the mixed gas always meets the blast furnace production requirements, thereby improving the blast furnace smelting intensity and iron production stability.

[0113] Please see Figure 4 and combined Figure 6According to some embodiments of this application, after controlling the oxygen flow regulating valve 15 to operate according to the oxygen demand flow rate so that the oxygen flow rate reaches the oxygen demand flow rate, the control method may further include: steps 240, 250 and 260.

[0114] Step 240: Obtain real-time oxygen content information.

[0115] Step 240 is a preliminary step for safety monitoring. After the oxygen flow rate is regulated in step 230, the controller acquires real-time oxygen content information again. This information is from the same source as the oxygen content information collected in step 210, and will not be described again here.

[0116] Step 250: If the real-time oxygen content information exceeds the preset threshold, control the oxygen quick-cut valve 17 to close and control the nitrogen quick-open valve 24 to open.

[0117] In step 250, the preset threshold is set based on the safety requirements of blast furnace production. The core is the allowable fluctuation range of oxygen content, typically using "20.9% + required oxygen enrichment rate A" as the baseline value. The preset threshold range is ±3% of the baseline value, i.e., the set range is [20.9% + A - 3%, 20.9% + A + 3%]. If the value exceeds this range, the real-time oxygen content is determined to exceed the preset threshold. For example, when the required oxygen enrichment rate A = 2%, the baseline value is 22.9%, and the preset threshold range is 19.9%-25.9%. If the real-time oxygen content detection value is 26.1% or 19.7%, safety protection is triggered.

[0118] When the real-time oxygen content exceeds the preset threshold, the controller immediately executes a safety linkage action: First, it sends a closing command to the oxygen quick-cut valve 17, whose response time is no more than 0.5 seconds, quickly cutting off the connection between the oxygen flow path and the oxygen mixer 2, stopping the oxygen input, and preventing the oxygen concentration from continuing to rise or fall abnormally from the source. At the same time, the controller sends an opening command to the nitrogen quick-open valve 24, whose response time is also no more than 0.5 seconds, quickly opening the nitrogen flow path, delivering nitrogen to the air duct 7 (the area between the oxygen mixer 2 and the blower 4), and using the inert properties of nitrogen to quickly dilute the oxygen concentration in the mixed gas, causing the oxygen content to quickly return to the set range.

[0119] In some examples, if the system is equipped with an oxygen vent valve 8, the controller will simultaneously send an opening command to the oxygen vent valve 8 to release the residual oxygen in the oxygen pipeline 21, thereby preventing the accumulation of oxygen in the pipeline and causing secondary safety hazards.

[0120] In other examples, if a temperature transmitter 5 is configured, the controller will combine real-time temperature data to determine the fault level. If the temperature exceeds the safety threshold (e.g., 300℃) at the same time, the safety control will be strengthened, and the nitrogen quick-opening valve 24 will be kept open until the oxygen content and temperature return to normal.

[0121] During the execution of safety protection actions, the controller will collect oxygen content data in real time and monitor the trend of oxygen concentration changes. When the oxygen content returns to the set range and remains stable for more than 30 seconds, the system can automatically or manually restore normal operation according to the preset strategy: When automatically restored, the controller first closes the nitrogen quick-opening valve 24 and the oxygen venting valve 8, and then slowly opens the oxygen quick-cut valve 17, and re-enters the cycle control of steps 210-230; When manually restored, the controller issues a fault clearance prompt, and the restoration operation is performed after confirmation by the staff.

[0122] Step 260: If the real-time oxygen content information is within the set range, repeat the step of calculating the required oxygen flow rate based on the required oxygen enrichment rate of the blast furnace, the real-time blast flow rate information, the real-time oxygen purity information, and the real-time oxygen content information.

[0123] Step 260 is a cyclical step to ensure the continuous and stable operation of the system. When the real-time oxygen content information obtained in step 240 is within the set range, it indicates that the current oxygen flow regulation effect meets the requirements, the oxygen concentration of the mixed gas is stable, and the system is in normal operation.

[0124] At this point, the controller does not need to trigger safety protection actions. Instead, it repeats the calculation process in step 220, that is, it recalculates the required oxygen flow rate X based on the real-time updated information on the required oxygen enrichment rate, blast flow rate, oxygen purity, and oxygen content of the blast furnace. This cycle execution period matches the parameter acquisition frequency, which can be 2Hz-10Hz, ensuring that the oxygen flow rate can track the dynamic changes of parameters such as blast flow rate and oxygen purity in real time, and avoiding deviations in the oxygen enrichment rate from the preset value due to parameter fluctuations.

[0125] During the cyclic control process, if the required oxygen enrichment rate A of the blast furnace is adjusted (by staff according to production needs), the controller will immediately use the new A value for calculation and quickly adjust the oxygen demand flow rate X to ensure that the oxygen enrichment rate matches the changes in production needs in a timely manner. If there are slight fluctuations in the blast flow rate or oxygen purity, the controller can quickly offset the impact of the fluctuations through cyclic calculation and valve fine-tuning to maintain a stable oxygen enrichment rate and ensure the continuity of the blast furnace smelting operation.

[0126] This control method, by adding real-time oxygen content monitoring and safety linkage, constructs a dual control system of "active adjustment + passive protection," effectively solving the problem of unreliable safety of blast furnace blower 4 when the oxygen mixing unit malfunctions in existing technologies. The high-frequency cycle calculation setting under normal operating conditions ensures that the oxygen enrichment rate can track parameter fluctuations in real time, further improving the accuracy and stability of oxygen enrichment rate control. The rapid linkage control under abnormal operating conditions can cut off oxygen and introduce nitrogen within milliseconds, significantly reducing the risks of fires and equipment damage caused by abnormal oxygen concentrations, providing core protection for the safe operation of blast furnace blower 4. It is also compatible with system expansion configurations, adapting to the diverse needs of complex industrial conditions.

[0127] Please see Figure 5 According to some embodiments of this application, the control method may further include steps 270 and 280.

[0128] Step 270: Obtain the temperature information of the air outlet of blower 4.

[0129] In step 270, temperature information acquisition relies on a temperature transmitter 5 installed in the air duct and located downstream of the blower 4. This temperature transmitter 5 monitors the temperature of the mixed gas at the blower 4 outlet in real time. Its detection range covers the normal operating temperature and abnormal high-temperature range (0℃-400℃) of the blast furnace blast, with a detection accuracy of no less than ±0.5℃, ensuring accurate capture of abnormal temperature changes. The temperature transmitter 5 converts the detected temperature signal into a 4-20mA standard analog signal, which is transmitted to the controller via a shielded cable. The transmission frequency is consistent with the acquisition frequency of parameters such as oxygen content and blower flow rate (2Hz-10Hz), enabling synchronous acquisition of temperature information and other control parameters, providing data support for the controller's comprehensive judgment. After receiving the temperature signal, the controller performs noise reduction processing using a built-in filtering module to eliminate instantaneous fluctuations caused by equipment vibration, environmental interference, etc., obtaining real-time temperature data reflecting the actual operating status of the blower 4.

[0130] Step 280: If the temperature information exceeds the temperature threshold, control the oxygen quick-cut valve 17 to close and control the nitrogen quick-open valve 24 to open.

[0131] Step 280 is a safety protection mechanism based on temperature anomalies. Its core is triggering targeted safety actions by determining a temperature threshold. The temperature threshold is set based on the operating parameters of the blower 4, the safe temperature range of the mixed gas, and the blast furnace production process requirements. It is typically set to 300℃, a safety critical value verified through industrial practice. When the temperature exceeds this value, the mixed gas poses a risk of spontaneous combustion and may cause overheating and damage to internal components of the blower 4. The controller compares the real-time temperature information obtained in step 270 with the preset temperature threshold in real time. If the real-time temperature data is greater than or equal to 300℃, it is determined that the temperature exceeds the threshold, and the blower 4 is in an abnormal operating state.

[0132] At this moment, the controller immediately activates the safety linkage control, sending a closing command to the oxygen quick-cut valve 17. This valve has a response time of no more than 0.5 seconds, quickly cutting off the oxygen flow path and stopping the delivery of oxygen to the oxygen mixer 2, eliminating the risk of combustion caused by excessive oxygen concentration at the source. At the same time, it sends an opening command to the nitrogen quick-open valve 24, which also opens rapidly within 0.5 seconds. Nitrogen is delivered to the air pipeline (the area between the oxygen mixer 2 and the blower 4) through the nitrogen pipeline 27. The inert nature of nitrogen quickly dilutes the oxygen concentration in the mixed gas, reducing the probability of spontaneous combustion. At the same time, the flow of nitrogen can carry away some heat, helping to reduce the temperature of the blower 4 outlet, providing double protection for equipment safety.

[0133] In some embodiments, when the blower 4 is triggered to stop due to mechanical failure, electrical failure, or other reasons, the control system of the blower 4 will send a stop fault electrical signal to the controller of this oxygen mixing safety control system. This electrical signal can be a digital switch signal, and the transmission method is the same as other control signals. It is transmitted quickly through a shielded cable to ensure that the controller receives the stop information when the blower 4 stops.

[0134] Upon receiving the fault shutdown signal from blower 4, the controller immediately determines that the system is in an emergency abnormal state without waiting for the detection results of oxygen content or temperature parameters, and immediately initiates safety linkage protection actions: First, it sends a closing command to oxygen quick-cut valve 17, which quickly cuts off the oxygen flow path, preventing oxygen from continuing to flow into the oxygen mixer 2 and the suction pipe of blower 4, thus avoiding oxygen accumulation in the pipeline after shutdown and resulting in an increase in oxygen concentration; at the same time, it sends an opening command to nitrogen quick-open valve 24, which opens rapidly and synchronously, allowing nitrogen to be continuously delivered to the suction pipe of blower 4 through nitrogen pipeline 27, diluting the residual oxygen in the pipeline and quickly reducing the oxygen concentration to a safe range, preventing the risk of spontaneous combustion or explosion caused by contact between the oxygen in the pipeline and equipment components after shutdown.

[0135] Regardless of whether the system experiences excessive oxygen content, abnormal temperature, or blower 4 malfunction and shutdown, it can quickly trigger safety protection, forming a comprehensive and seamless safety protection system. This completely eliminates the safety hazard of oxygen accumulation in the pipeline when blower 4 malfunctions and shuts down, further adapting to various sudden abnormal situations in industrial scenarios and ensuring the safety of equipment and personnel.

[0136] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0137] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0138] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0139] In the description of this application, "multiple" means two or more.

[0140] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them.

[0141] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0142] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0143] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A safety control system for oxygen mixing before a blast furnace blower, characterized in that, include: Air flow path, oxygen flow path, nitrogen flow path, and controller; The air flow path includes an air duct, and an air filter, an oxygen mixer, an oxygen content transmitter, a blower, and a blower flow transmitter connected in series along the air flow direction. The oxygen flow path includes an oxygen pipeline, and an oxygen filter, an oxygen purity transmitter, an oxygen pressure regulating valve, an oxygen pressure transmitter, an oxygen flow regulating valve, an oxygen flow transmitter, an oxygen quick-cut valve, and an oxygen check valve connected in series along the oxygen flow direction. The output end of the oxygen pipeline is connected to the oxygen mixer. The nitrogen flow path includes a nitrogen pipeline, and a nitrogen quick-opening valve and a nitrogen check valve connected in series along the flow direction of nitrogen. The output end of the nitrogen pipeline is connected to the air pipeline. The controller is electrically connected to the oxygen content transmitter, the blower flow transmitter, the oxygen purity transmitter, the oxygen pressure regulating valve, the oxygen pressure transmitter, the oxygen flow regulating valve, the oxygen flow transmitter, the oxygen quick-cut valve, and the nitrogen quick-open valve, respectively. The controller is used to control the operation of the oxygen pressure regulating valve, the oxygen flow regulating valve, the oxygen quick-cut valve, and the nitrogen quick-open valve according to the oxygen content information, the blower flow information, and the oxygen purity information.

2. The blast furnace blower pre-blowing oxygen mixing safety control system according to claim 1, characterized in that, A temperature transmitter is installed on the air duct, located behind the blower along the airflow direction, and is electrically connected to the controller.

3. The blast furnace blower pre-blowing oxygen mixing safety control system according to claim 1, characterized in that, A sampling tube is connected to the air pipeline, and the oxygen content transmitter is installed on the sampling tube.

4. The blast furnace blower pre-blowing oxygen mixing safety control system according to claim 3, characterized in that, The sampling tubes are provided in at least two, and two adjacent sampling tubes are arranged at an angle along the circumference of the air duct. The oxygen content transmitter is provided in at least two corresponding to the sampling tubes.

5. The blast furnace blower pre-blowing oxygen mixing safety control system according to any one of claims 1-4, characterized in that, An oxygen vent pipe is connected to the oxygen pipeline. Along the direction of oxygen flow, the oxygen vent pipe is located in front of the oxygen filter. An oxygen vent valve is provided on the oxygen vent pipe, and the oxygen vent valve is electrically connected to the controller.

6. The blast furnace blower pre-blowing oxygen mixing safety control system according to any one of claims 1-4, characterized in that, The oxygen flow path also includes an oxygen buffer tank, which is connected to the oxygen pipeline via an oxygen buffer pipe. The oxygen buffer pipe is connected to the portion of the oxygen pipeline located between the oxygen filter and the oxygen purity transmitter. An oxygen buffer tank shut-off valve is provided on the oxygen buffer pipe. The nitrogen flow path also includes a nitrogen buffer tank, which is connected to the nitrogen pipeline via a nitrogen buffer pipe along the nitrogen flow direction. The nitrogen buffer pipe is connected to the portion of the nitrogen pipeline located in front of the nitrogen quick-opening valve, and a nitrogen buffer tank shut-off valve is provided on the nitrogen buffer pipe.

7. The blast furnace blower pre-blowing oxygen mixing safety control system according to any one of claims 1-4, characterized in that, Along the direction of oxygen flow, a first shut-off valve is provided on the oxygen pipeline in front of the oxygen filter, and a second shut-off valve is provided in the pipeline behind the oxygen check valve; and / or, Along the flow direction of nitrogen, a third shut-off valve is provided on the nitrogen pipeline at the position in front of the nitrogen quick-opening valve, and a fourth shut-off valve is provided at the position behind the nitrogen check valve.

8. A method for safe control of oxygen mixing before the blast furnace blower, based on the safe control system for oxygen mixing before the blast furnace blower as described in any one of claims 1-7, characterized in that, The control method includes: Obtain the required oxygen enrichment rate, blast flow rate, oxygen purity, and oxygen content for the blast furnace; Based on the required oxygen enrichment rate of the blast furnace, real-time blast flow rate, real-time oxygen purity, and real-time oxygen content, calculate the required oxygen flow rate. The oxygen flow regulating valve and / or oxygen pressure regulating valve are activated according to the oxygen demand flow rate to ensure that the oxygen flow rate reaches the oxygen demand flow rate.

9. The method for safe control of oxygen mixing before the blast furnace blower according to claim 8, characterized in that, After controlling the oxygen flow regulating valve to operate according to the oxygen demand flow rate to achieve the required oxygen flow rate, the control method further includes: Obtain real-time oxygen content information; If the real-time oxygen content exceeds the preset threshold, the oxygen quick-cut valve will be closed and the nitrogen quick-open valve will be opened. If the real-time oxygen content information is within the set range, the step of calculating the required oxygen flow rate based on the required oxygen enrichment rate of the blast furnace, the real-time blast flow rate information, the real-time oxygen purity information, and the real-time oxygen content information is repeated.

10. The method for safe control of oxygen mixing before the blast furnace blower according to claim 8, characterized in that, The control method further includes: Obtain the temperature information of the blower outlet; If the temperature exceeds the temperature threshold, the oxygen quick-cut valve is closed and the nitrogen quick-open valve is opened.

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