A gas supply pressurization device to enhance the bottom blowing effect of a converter

Abstract

This invention relates to a gas supply pressurization device for enhancing the bottom blowing effect in a converter, comprising a pressurization unit, an intelligent control unit, a safety interlock unit, and a rapid switching unit. The pressurization unit employs a two-stage pressurization module, in conjunction with an interstage cooler, to progressively increase the gas pressure from 0.6-0.8 MPa and stably output it to 1.8-2.5 MPa. The intelligent control unit utilizes a PLC controller and an adaptive PID algorithm to achieve precise gas supply by closed-loop regulation of pressure and flow rate based on process parameters such as molten pool carbon content and temperature. The safety interlock unit, in conjunction with the rapid switching unit, can quickly switch to a bypass and release pressure in case of pressure exceeding limits or malfunction, ensuring continuous gas supply and equipment safety. This invention significantly improves the bottom blowing stirring kinetic energy without modifying the plant's pipeline network, effectively reduces the final carbon-oxygen product and oxygen content in molten steel, reduces deoxidizer consumption, and improves steel cleanliness. It has the advantages of compact structure, precise control, safety and reliability, and ease of promotion.

Description

Technical Field

[0001] This patent application belongs to the technical field of steelmaking equipment for converters in iron and steel metallurgy, and more specifically, it relates to a gas supply and pressurization device to enhance the bottom blowing effect of converters. Background Technology

[0002] In converter steelmaking, blowing inert gases (such as Ar and N2) into the molten pool through gas supply elements (such as permeable bricks) arranged at the bottom of the furnace is an important means to enhance stirring, homogenize composition and temperature, and promote chemical reactions. The intensity of bottom blowing stirring directly determines the kinetic conditions of the molten pool, which in turn affects the final carbon-oxygen product, the oxygen content of the molten steel, and the consumption of deoxidizer.

[0003] Currently, the operating pressure of bottom-blown gas supply pipelines in converters within the industry is generally low, typically ranging from 0.6 to 1.0 MPa. At this pressure level, the effective flow rate of gas after passing through the gas supply element is limited, resulting in insufficient stirring intensity and poor metallurgical performance. Specifically, this manifests as a high final carbon-oxygen product (averaging around 0.0026) and a high final oxygen level in the molten steel. This not only generates more deoxidation products (such as SiO2 and Al2O3 inclusions), affecting the cleanliness of the molten steel, but also significantly increases the consumption of deoxidizing alloys such as ferroaluminum and ferrosilicon, driving up smelting costs.

[0004] While the industry generally recognizes that increasing bottom-blowing pressure is key to addressing the aforementioned problems, directly raising the overall plant gas supply pressure to above 1.8 MPa presents significant challenges: firstly, upgrading the plant's pipeline network requires substantial investment; secondly, high-pressure gas places extremely high demands on the sealing and safety of existing pipelines; and thirdly, a dedicated device is needed to accurately, stably, and safely provide high-pressure gas, seamlessly integrating with the existing converter control system. Therefore, developing a dedicated pressurization device installed at the end of existing gas supply pipelines is both a pressing practical need and of significant economic value. Summary of the Invention

[0005] The purpose of this invention is to provide a gas supply pressurization device to enhance the bottom blowing effect of converters, aiming to solve the problems of insufficient pressure and weak stirring intensity in existing converter bottom blowing gas supply systems, which lead to poor metallurgical results. This device integrates a pressurization system with dual-stage pressurization, intelligent control, and multiple safety protections at the end of the existing gas source pipeline. Without modifying the plant's main pipeline, it stably increases the gas supply pressure to the high-pressure range required by the smelting process, thereby enhancing molten pool stirring, reducing the final carbon-oxygen product, improving steel cleanliness, and lowering production costs.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A gas supply pressurization device for enhancing the bottom blowing effect of a converter includes a pipeline integrated into the gas source pipe of the converter bottom blowing gas supply system between the end of the gas source pipe and the gas supply element at the bottom of the furnace. The gas source pipe is equipped with a pre-filter. The device also includes a pressurization unit, an intelligent control unit, a safety interlock unit, and a quick switching unit.

[0008] The pressurization unit is physically connected in series with the main gas supply pipeline to receive low-pressure gas from the gas source and increase its pressure to the target high pressure. The pressurization unit includes a two-stage booster module, which consists of a first-stage scroll compressor, an interstage cooler, a gas-water separator, and a second-stage hydraulic coupling booster pump connected in series along the gas flow direction via high-pressure alloy steel pipes. The first-stage scroll compressor initially increases the gas source pressure from 0.6-0.8 MPa to 1.2-1.5 MPa. After being cooled by the interstage cooler and dehydrated by the gas-water separator, the gas enters the second-stage hydraulic coupling booster pump, where it is finally boosted and stably output to the target high pressure of 1.8-2.5 MPa.

[0009] The intelligent control unit is connected to the pressurization unit, safety interlock unit, fast switching unit, and converter main control system via signal lines. It is used to receive process parameters and output control commands. The intelligent control unit includes a PLC controller, pressure / flow sensors connected to the PLC controller, and an HMI (human-machine interface). The pressure / flow sensors are installed at the inlet, interstage position, and outlet of the pressurization unit to collect pressure / flow data in real time. The PLC controller is also connected to the first-stage scroll compressor and the second-stage hydraulic coupling booster pump. The PLC controller has a built-in adaptive PID control algorithm. This algorithm sets the target pressure value based on the received carbon content and temperature of the molten steel in the converter pool and the blowing stage, and dynamically adjusts the speed of the variable frequency motor of the first-stage scroll compressor and the servo oil pressure of the second-stage hydraulic coupling booster pump to achieve precise closed-loop control of the output gas pressure and flow.

[0010] The safety interlock unit is connected to the output pipeline of the pressurization unit to monitor pressure over-limit and execute safety actions. The safety interlock unit includes a pressure relief branch connected in parallel to the main gas supply pipeline and a backup bypass also connected in parallel to the main gas supply pipeline. The backup bypass cooperates with the pressure relief branch through a three-way ball valve. The pressure relief branch is responsible for over-pressure relief, and the backup bypass is responsible for supply protection in case of failure. A mechanical safety valve and an electromagnetic pilot-operated pressure relief valve are installed in sequence on the pressure relief branch. The mechanical safety valve, electromagnetic pilot-operated pressure relief valve, and three-way ball valve are all connected to the PLC controller. When the pressure / flow sensor detects that the outlet pressure exceeds 2.6 MPa or is lower than 1.6 MPa, the PLC controller immediately triggers the electromagnetic pilot-operated pressure relief valve to open and release pressure, and at the same time controls the three-way ball valve to switch to the backup bypass to ensure continuous gas supply to the furnace bottom gas supply element.

[0011] The quick-switching unit, integrated into the piping system, enables uninterrupted switching between pressurization and bypass modes. The quick-switching unit includes a main electric butterfly valve and a bypass electric butterfly valve connected in parallel. A three-way ball valve is used to select between the pressurization branch and the bypass branch. The main electric butterfly valve is located on the pressurization branch, which is also connected in parallel to the main gas supply line. The bypass electric butterfly valve is located on the bypass branch, which is connected to the standby bypass. The three-way ball valve is located at the connection between the pressurization branch and the standby bypass. The main electric butterfly valve and the bypass electric butterfly valve are connected to the PLC controller of the intelligent control unit.

[0012] In normal pressurization mode, the main electric butterfly valve is open, the bypass electric butterfly valve is closed, and the three-way ball valve is switched to connect with the pressurization unit, allowing gas to flow through the pressurization unit. When it is necessary to switch to the bypass, the main electric butterfly valve is closed when the intelligent control unit issues a switching command or when the safety interlock is triggered, and the bypass electric butterfly valve is opened simultaneously. The three-way ball valve is switched to connect with the bypass, achieving a seamless switching of the gas supply path.

[0013] Furthermore, the interstage cooler adopts an annular sleeve-type water-cooled structure, and the cooling water inlet is equipped with an electric regulating valve. The electric regulating valve is connected to the PLC controller, and the opening degree of the electric regulating valve is adjusted by the PLC controller according to the interstage gas temperature signal to ensure that the gas temperature entering the second-stage hydraulic coupling booster pump is below 50℃.

[0014] Furthermore, the hydraulic circuit system of the second-stage hydraulic coupling booster pump integrates an oil temperature cooler and a precision oil filter to ensure the stability and reliability of the hydraulic system, thereby guaranteeing the extreme stability of the output pressure, with a pressure fluctuation range of no more than ±0.05 MPa.

[0015] Furthermore, the HMI (Human Machine Interface) provides a library of pressure-flow setting curve templates. Operators can select preset or custom "pressure-blowing time" curves according to the smelting process requirements of different steel grades, which will be automatically executed by the intelligent control unit.

[0016] Furthermore, all high-pressure pipeline connections adopt a metal hard-seal flange structure, with the sealing surface material being hard alloy, to ensure long-term sealing reliability under high-pressure conditions above 1.8 MPa.

[0017] Furthermore, the adaptive PID control algorithm runs within the PLC controller, automatically adjusting the proportional coefficient K of the PID controller based on different stages of converter blowing (such as early blowing, middle blowing, and blowing end) and the state of the molten pool (carbon content, temperature). p Integral coefficient K i and differential coefficient K dTo adapt to different requirements for gas flow response speed and stability under different working conditions, it specifically includes three logic modules: process parameter preprocessing module, parameter self-tuning PID calculation module, and execution action module;

[0018] Process parameter preprocessing module: Receives real-time carbon content data uploaded by the converter main control system. Real-time temperature and current refining time Based on the preset "pressure-blowing time" curve template in the HMI (Human Machine Interface), the basic target pressure setpoint for the current moment is calculated. Based on the real-time molten pool status Fine-tuning is performed; for example, when the carbon content is detected to be higher than expected, the algorithm determines that the decarbonization rate needs to be accelerated, automatically increasing the target pressure value to increase the stirring kinetic energy. Example of formula correction:

[0019] ,

[0020] SP target The target pressure value;

[0021] C set T set These are the carbon content setting value and the temperature setting value, respectively.

[0022] K c K t This is a correction factor;

[0023] The parameter self-tuning PID calculation module: Based on the characteristic values ​​of the blowing stage, it calls the corresponding PID parameter set to perform calculations and outputs the control quantity. ;

[0024] Action Module: The PLC controller calculates and outputs control quantities based on the self-tuning PID controller. Simultaneously, it sends frequency adjustment commands to the inverter of the first-stage scroll compressor and current signals to the electro-hydraulic servo valve of the second-stage hydraulic coupling booster pump, thereby achieving two-stage coordinated control.

[0025] Furthermore, in the parameter self-tuning PID calculation module, "calling the corresponding PID parameter group for calculation based on the characteristic values ​​of the blowing stage" means that, since the different stages of converter blowing include the early blowing stage, the middle blowing stage, and the end blowing stage, the early blowing parameter group, the middle blowing parameter group, and the end blowing parameter group are called respectively. The specific implementation steps are as follows:

[0026] Step 1: Pre-refining stage (0-5 minutes) - Quick response mode

[0027] Operating characteristics: The molten pool temperature is relatively low, and the oxidation of ferrosilicon and manganese is intense, requiring a large bottom-blowing flow rate for rapid slag formation, but the pressure accuracy requirements are relatively low.

[0028] PID parameter tuning strategy: PLC calls the "preliminary parameter group", parameter example: setting the proportional coefficient K. p Larger (e.g., K) p =2.5), integral coefficient K i Smaller (e.g., K) i =0.1), differential coefficient K d This setting is moderate and can improve the system's response speed, enabling the first-stage scroll compressor and the second-stage hydraulic coupling booster pump to quickly reach high-speed output and meet the initial large flow rate requirements.

[0029] Step Two: Mid-stage of refining (5-12 minutes) – Stabilization and adjustment mode

[0030] Operating conditions: The carbon-oxygen reaction is intense, and the temperature of the molten pool rises. At this time, it is necessary to maintain a moderate stirring intensity and avoid large pressure fluctuations that could cause splashing.

[0031] PID parameter tuning strategy: The PLC controller automatically switches to the "intermediate parameter group" based on the time signal or the carbon-oxygen reaction rate signal. Parameter example: Appropriately reduce K. p (e.g., K) p =1.8), increase K i (e.g., K) i =0.3), this adjustment suppresses overshoot and ensures a smooth transition of gas supply pressure within the range of 1.8-2.5MPa;

[0032] Step 3: End of blowing process (12-15 minutes) – High-precision constant temperature and pressure mode

[0033] Operating conditions: Near the end point, the carbon content of the molten steel is low and the oxygen content is high, requiring extremely high uniformity of bottom blowing agitation in order to reduce the carbon-oxygen product.

[0034] PID parameter tuning strategy: PLC switches to "Endpoint parameter group". Parameter example: using a smaller K. p (e.g., K) p =1.2) and larger K i (e.g., K) i =0.5), and introduce the differential coefficient K. d Predictive control is implemented, and the algorithm is extremely sensitive to pressure deviations. It can precisely control the second-stage hydraulic coupling booster pump, so that the outlet pressure fluctuation is strictly controlled within ±0.05MPa.

[0035] Due to the adoption of the above technical solution, the beneficial effects achieved by this invention are:

[0036] Significantly improves smelting indicators and steel quality: By increasing the bottom-blown gas supply pressure from the conventional 0.6-1.0 MPa to 1.8-2.5 MPa, the stirring kinetic energy of the bottom-blown gas is greatly increased. This greatly improves the kinetic conditions of the molten pool, promotes the homogenization of steel composition and temperature, and significantly reduces the carbon-oxygen product at the converter endpoint (from an average of 0.0026 to an even lower level). This effectively reduces the oxygen content at the steel endpoint, reduces the formation of deoxidation products (such as Al2O3 inclusions), and significantly improves the cleanliness of the molten steel.

[0037] Reduced production consumption and costs: Due to the reduced oxygen content at the final stage of molten steel, the consumption of alloys such as ferroaluminum and ferrosilicon required for deoxidation is correspondingly reduced, directly lowering smelting costs. Simultaneously, intense stirring promotes slag formation and chemical reactions, shortening smelting time and improving converter production efficiency.

[0038] Precise process adaptability and intelligent control: This invention employs an intelligent control unit with a built-in adaptive PID algorithm, which can adjust pressure and flow rate in real time according to the carbon content of the molten pool, temperature, and blowing stage. Combined with the curve template library of the HMI (Human-Machine Interface), it realizes customized gas supply strategies for different steel grades, which is not only easy to operate but also has high control precision, avoiding the lag and blindness of manual operation.

[0039] Extremely high system reliability and safety: Employing dual-stage pressurization and interstage cooling technology, it balances pressurization capacity with equipment lifespan. In particular, the dual protection design of the safety interlock unit and the rapid switching unit allows for instantaneous switching to bypass or pressure relief in case of pressure over-limit or equipment failure, ensuring continuous gas supply to the furnace bottom gas supply elements and effectively preventing blockage of the permeable bricks or even furnace leakage accidents caused by gas supply interruption. The combination of the hydraulic coupling device and the precision oil filter ensures the stability of the output pressure and avoids pulse impacts on the gas supply elements.

[0040] Easy to promote, apply and upgrade: This device adopts a modular and integrated design and is installed at the end of the main gas supply pipeline. It does not require large-scale transformation of the plant's huge high-pressure gas supply network. It has low investment, short construction period and small footprint, making it very suitable for energy saving and consumption reduction and potential tapping transformation of existing converter workshops. It has extremely high promotion value and economic benefits. Attached Figure Description

[0041] Figure 1 This is a schematic diagram illustrating the system structure and principle of the present invention.

[0042] Figure 2 This is a schematic diagram of the pressurization unit structure.

[0043] Figure 3 This is a schematic diagram of the intelligent control unit structure.

[0044] Figure 4This is a schematic diagram of the safety interlocking unit and the quick switching unit.

[0045] Figure 5 This is a connection block diagram of the present invention.

[0046] The components include: 1. Gas source pipe; 2. Pre-filter; 3. Pressurization unit; 4. High-pressure gas transmission pipe; 5. Intelligent control unit; 6. Safety interlock unit; 7. Quick switching unit; 8. Bottom gas supply element.

[0047] First-stage scroll compressor 3-1; Second-stage hydraulic coupling booster pump 3-2; Gas-water separator 3-3; Turbocharger 3-4;

[0048] 5-1 PLC controller; 5-2 HMI (Human Machine Interface); 5-3 Pressure / flow sensor;

[0049] Mechanical safety valve 6-1; Solenoid pressure relief valve 6-2; Three-way ball valve 6-3; Backup bypass 6-4; Pressure relief branch 6-5;

[0050] Main line electric butterfly valve 7-1; bypass electric butterfly valve 7-2; bypass branch valve 7-3; pressurized branch valve 7-4. Detailed Implementation

[0051] The present invention will be further described in detail below with reference to the embodiments.

[0052] A gas supply pressurization device to enhance the bottom blowing effect of converter is integrated and installed between the end of the main gas supply pipeline of the converter bottom blowing gas supply system and the gas supply element at the bottom of the furnace. It aims to solve the problem of insufficient stirring intensity of the molten pool and poor metallurgical effect caused by the low gas supply pressure in the existing system.

[0053] like Figures 1 to 5 As shown, this invention provides a gas supply pressurization device to enhance the bottom blowing effect of a converter. The device is integrated and installed on the pipeline between the end of the main gas source pipeline of the converter bottom blowing gas supply system and the gas supply element at the bottom of the converter. A pre-filter 2 is installed on the gas source pipeline 1. The device adopts a modular steel structure base design and includes four core components: a pressurization unit 3, an intelligent control unit 5, a safety interlock unit 6, and a quick switching unit 7.

[0054] In specific implementation, such as Figure 1 As shown, the gas source pipe 1 is connected to the inlet of the device and is equipped with a pre-filter 2 to remove impurities from the gas. The filtered gas enters the pressurization unit 3 for pressurization treatment, and the treated high-pressure gas is output through the high-pressure gas transmission pipe 4, and finally transported to the converter bottom through the pipeline to the gas supply element 8 at the furnace bottom.

[0055] The pressurization unit 3, as the core power component of this device, is physically connected in series in the main gas supply pipeline. It receives low-pressure gas from the gas source and increases its pressure to the target high pressure. The specific structure is as follows: Figure 2 As shown. The pressurization unit 3 employs a two-stage pressurization module, which includes a first-stage scroll compressor 3-1, an interstage cooler, a gas-water separator 3-3, and a second-stage hydraulically coupled booster pump 3-2, connected in series along the gas flow direction via high-pressure alloy steel pipes. Between the first-stage scroll compressor 3-1 and the second-stage hydraulically coupled booster pump 3-2, an interstage cooler and a gas-water separator 3-3 are cascaded. Low-pressure gas with a source pressure of 0.6-0.8 MPa first enters the first-stage scroll compressor 3-1 and is initially compressed to 1.2-1.5 MPa; subsequently, the high-temperature gas enters the interstage cooler to cool it, ensuring the temperature is below 50°C, and after condensate is removed by the gas-water separator 3-3, it enters the second-stage hydraulically coupled booster pump 3-2. The second-stage hydraulically coupled booster pump 3-2 utilizes the servo hydraulic control of the hydraulic system to ultimately boost the gas pressure and stably output it to the target high pressure of 1.8-2.5 MPa. In this embodiment, the interstage cooler preferably adopts an annular sleeve-type water-cooled structure, and its cooling water inlet is equipped with an electrically adjustable valve. This electrically adjustable valve is connected to the intelligent control unit 5 and automatically adjusts its opening degree according to the real-time temperature. At the same time, the hydraulic oil circuit system of the second-stage hydraulic coupling booster pump 3-2 integrates an oil temperature cooler and a precision oil filter to maintain a constant and clean hydraulic oil temperature and ensure that the output pressure fluctuation range is no greater than ±0.05 MPa.

[0056] The intelligent control unit 5 is the control center of the device. It is connected to the pressurization unit 3, safety interlock unit 6, rapid switching unit 7, and converter main control system via signal lines. It is used to receive process parameters and output control commands, and its structure is as follows: Figure 3As shown, the system mainly includes a PLC controller 5-1, an HMI (Human-Machine Interface) 5-2 connected to the PLC controller 5-1, and a pressure / flow sensor 5-3. The PLC controller 5-1 is connected to the pressurization unit 3, the safety interlock unit 6, and the converter main control system via signal lines. The pressure / flow sensor 5-3 includes a pressure sensor group and a flow sensor. The pressure sensor group is installed at the inlet, interstage position, and outlet of the pressurization unit 3, respectively, while the flow sensor is installed on the high-pressure gas transmission pipe 4 for real-time acquisition of pressure and flow data. The PLC controller 5-1 is also connected to the first-stage scroll compressor 3-1 and the second-stage hydraulic coupling booster pump 3-2. The PLC controller 5-1 has a built-in adaptive PID control algorithm that sets the target pressure value based on the received process parameters such as the carbon content, temperature, and blowing stage of the molten steel in the converter pool. It dynamically adjusts the variable frequency motor speed of the first-stage scroll compressor 3-1 and the servo hydraulic pressure of the second-stage hydraulic coupling booster pump 3-2 to achieve precise closed-loop control of the output gas pressure and flow. The HMI 5-2 provides a pressure-flow setting curve template library. Operators can select preset curves or customize "pressure-blowing time" curves according to different steel grades. The control unit executes automatically to achieve precise closed-loop control.

[0057] The "adaptive PID control algorithm" of this invention is not a simple general PID control, but a multi-modal parameter self-tuning control strategy that combines the characteristics of metallurgical processes. Its core lies in automatically adjusting the proportional coefficient (Kp), integral coefficient (Ki), and derivative coefficient (Kd) of the PID controller according to different stages of converter blowing (such as the early, middle, and final stages of blowing) and the state of the molten pool (carbon content, temperature), so as to adapt to the different requirements for gas flow response speed and stability under different operating conditions.

[0058] The adaptive PID control algorithm runs inside the PLC controller 5-1. Based on different stages of converter blowing (such as early blowing, middle blowing, and blowing endpoint) and the state of the molten pool (carbon content, temperature), it automatically adjusts the proportional coefficient K of the PID controller. p Integral coefficient K i and differential coefficient K d To adapt to different requirements for gas flow response speed and stability under different working conditions, it specifically includes three logic modules: process parameter preprocessing module, parameter self-tuning PID calculation module, and execution action module;

[0059] Process parameter preprocessing module: Receives real-time carbon content data uploaded by the converter main control system. Real-time temperature and current refining time Based on the preset "pressure-blowing time" curve template in HMI 5-2, the basic target pressure setpoint for the current moment is calculated. Based on the real-time molten pool status Fine-tuning is performed; for example, when the carbon content is detected to be higher than expected, the algorithm determines that the decarbonization rate needs to be accelerated, automatically increasing the target pressure value to increase the stirring kinetic energy. Example of formula correction:

[0060] ,

[0061] SP target The target pressure value;

[0062] C set T set These are the carbon content setting value and the temperature setting value, respectively.

[0063] K c K t This is a correction factor;

[0064] The parameter self-tuning PID calculation module: Based on the characteristic values ​​of the blowing stage, it calls the corresponding PID parameter set to perform calculations and outputs the control quantity. ;

[0065] Action Execution Module: PLC controller 5-1 calculates and outputs control quantities based on self-tuning PID. Simultaneously, it sends frequency adjustment commands to the inverter of the first-stage scroll compressor 3-1 and current signals to the electro-hydraulic servo valve of the second-stage hydraulic coupling booster pump 3-2, thereby achieving dual-stage coordinated control.

[0066] In the parameter self-tuning PID calculation module, "calling the corresponding PID parameter set for calculation based on the characteristic values ​​of the blowing stage" means that, since the different stages of converter blowing include the early blowing stage, the middle blowing stage, and the end blowing stage, the parameter sets for the early blowing stage, the middle blowing stage, and the end blowing stage are called respectively. The specific implementation steps are as follows:

[0067] Step 1: Pre-refining stage (0-5 minutes) - Quick response mode

[0068] Operating characteristics: The molten pool temperature is relatively low, and the oxidation of ferrosilicon and manganese is intense, requiring a large bottom-blowing flow rate for rapid slag formation, but the pressure accuracy requirements are relatively low.

[0069] PID parameter tuning strategy: PLC calls the "preliminary parameter group", parameter example: setting the proportional coefficient K. p Larger (e.g., K) p =2.5), integral coefficient K i Smaller (e.g., K) i =0.1), differential coefficient K dThe setting is moderate, which can improve the system's response speed, allowing the first-stage scroll compressor 3-1 and the second-stage hydraulic coupling booster pump 3-2 to quickly reach high-speed output and meet the initial large flow rate requirements.

[0070] Step Two: Mid-stage of refining (5-12 minutes) – Stabilization and adjustment mode

[0071] Operating conditions: The carbon-oxygen reaction is intense, and the temperature of the molten pool rises. At this time, it is necessary to maintain a moderate stirring intensity and avoid large pressure fluctuations that could cause splashing.

[0072] PID parameter tuning strategy: The PLC controller 5-1 automatically switches to the "intermediate parameter group" based on the time signal or the carbon-oxygen reaction rate signal. Parameter example: Appropriately reduce K. p (e.g., K) p =1.8), increase K i (e.g., K) i =0.3), this adjustment suppresses overshoot and ensures a smooth transition of gas supply pressure within the range of 1.8-2.5MPa;

[0073] Step 3: End of blowing process (12-15 minutes) – High-precision constant temperature and pressure mode

[0074] Operating conditions: Near the end point, the carbon content of the molten steel is low and the oxygen content is high, requiring extremely high uniformity of bottom blowing agitation in order to reduce the carbon-oxygen product.

[0075] PID parameter tuning strategy: PLC switches to "Endpoint parameter group". Parameter example: using a smaller K. p (e.g., K) p =1.2) and larger K i (e.g., K) i =0.5), and introduce the differential coefficient K. d Predictive control is performed, and the algorithm is extremely sensitive to pressure deviation. It can accurately control the second-stage hydraulic coupling booster pump 3-2, so that the outlet pressure fluctuation is strictly controlled within ±0.05MPa.

[0076] Through the above embodiments, the adaptive PID algorithm of the present invention can optimize control parameters in real time according to the process progress, significantly improving the dynamic response characteristics and steady-state accuracy of the system.

[0077] The structure of the safety interlocking unit 6 and the quick switching unit 7 is as follows: Figure 4As shown, this is used to ensure the safe operation of the system and the continuity of gas supply. The safety interlock unit 6 is connected to the output pipeline of the pressurization unit 3 and is used to monitor pressure over-limit and execute safety actions. The safety interlock unit 6 includes a pressure relief branch 6-5 connected in parallel to the main gas supply pipeline, and a backup bypass 6-4 also connected in parallel to the main gas supply pipeline. The backup bypass 6-4 cooperates with the pressure relief branch 6-5 through a three-way ball valve 6-3. The pressure relief branch 6-5 is responsible for over-pressure relief, and the backup bypass 6-4 is responsible for ensuring supply during failure.

[0078] A mechanical safety valve 6-1 and an electromagnetic pilot-operated pressure relief valve 6-2 are installed sequentially on the pressure relief branch 6-5. The mechanical safety valve 6-1, the electromagnetic pilot-operated pressure relief valve 6-2, and the three-way ball valve 6-3 are all connected to the PLC controller 5-1. When the pressure / flow sensor 5-3 detects that the outlet pressure exceeds 2.6 MPa or is lower than 1.6 MPa, the PLC controller 5-1 immediately triggers the electromagnetic pilot-operated pressure relief valve 6-2 to open and relieve pressure, and at the same time controls the three-way ball valve 6-3 to switch to the standby bypass to ensure continuous gas supply to the gas supply element at the bottom of the furnace.

[0079] The quick-switching unit 7, integrated into the pipeline system, is used to achieve uninterrupted switching between pressurization mode and bypass mode. The quick-switching unit 7 includes a pair of electric butterfly valves (main electric butterfly valve 7-1 and bypass electric butterfly valve 7-2) arranged in parallel, and a three-way ball valve 6-3 for selecting the pressurization branch 7-4 or the bypass branch 7-3. The main electric butterfly valve 7-1 is located on the pressurization branch 7-4, which is also connected in parallel to the main gas supply pipeline. The bypass electric butterfly valve 7-2 is located on the bypass branch 7-3, which is connected to the standby bypass 6-4. The three-way ball valve 6-3 is located at the connection between the pressurization branch 7-4 and the standby bypass 6-4. The main electric butterfly valve 7-1 and the bypass electric butterfly valve 7-2 are connected to the PLC controller 5-1 of the intelligent control unit 5.

[0080] The backup bypass 6-4 and the pressure relief branch 6-5 together constitute a safety protection mechanism. Specifically, when the system detects a fault (such as low pressure or a pressurization unit malfunction), the PLC controller 5-1 will control the three-way ball valve 6-3 to operate, cutting off the passage to the pressurization branch 7-4 and connecting the backup bypass 6-4. The pressure relief branch 6-5 and the backup bypass 6-4 are two independent parallel branches that jointly ensure the safety of the system: the pressure relief branch 6-5 is responsible for overpressure relief, and the backup bypass 6-4 is responsible for fault-based power supply.

[0081] The pressurization branch 7-4 and the pressure relief branch 6-5 are physically connected in parallel to the main gas supply pipeline (between the inlet and outlet sides of pressurization unit 3). During normal operation, the pressure relief branch 6-5 is closed, and the pressurization branch 7-4 is operational. When the outlet pressure of the pressurization branch 7-4 exceeds a threshold (e.g., 2.6 MPa), the pressure relief branch 6-5 opens, releasing some gas to reduce the pressure in the pressurization branch 7-4 and the outlet pipeline, thus providing overpressure protection.

[0082] In normal pressurization mode, PLC controller 5-1 controls the main electric butterfly valve 7-1 to open, the bypass electric butterfly valve 7-2 to close, and the three-way ball valve 6-3 to switch to the pressurization unit 3 and be in the pressurization path position, allowing gas to flow through the pressurization unit 3 for pressurization. When the pressure sensor detects that the outlet pressure exceeds 2.6 MPa or falls below 1.6 MPa, PLC controller 5-1 immediately triggers the safety interlock, issuing a switching command or safety interlock trigger: on the one hand, it controls the electromagnetic pilot-operated pressure relief valve 6-2 to open for pressure relief; on the other hand, it issues a command to control the main electric butterfly valve 7-1 to close, the bypass electric butterfly valve 7-2 to open simultaneously, and the three-way ball valve 6-3 to switch to the standby bypass position. At this time, the gas is supplied directly through the bypass without pressurization, ensuring continuous gas supply to the furnace bottom gas supply element, preventing abnormal pressure from damaging the equipment or causing blockage of the permeable bricks due to gas interruption, and achieving a seamless switching of the gas supply path.

[0083] The interstage cooler adopts an annular sleeve water-cooled structure. The cooling water inlet is equipped with an electric regulating valve, which is connected to the PLC controller 5-1. The opening degree of the electric regulating valve is adjusted by the PLC controller 5-1 according to the interstage gas temperature signal to ensure that the gas temperature entering the second-stage hydraulic coupling booster pump 3-2 is below 50℃.

[0084] The hydraulic circuit system of the second-stage hydraulic coupling booster pump 3-2 integrates an oil temperature cooler and a precision oil filter to ensure the stability and reliability of the hydraulic system, thereby guaranteeing the extreme stability of the output pressure, with a pressure fluctuation range of no more than ±0.05Mpa.

[0085] The HMI (Human Machine Interface) 5-2 provides a pressure-flow setting curve template library. Operators can select preset or custom "pressure-blowing time" curves according to the smelting process requirements of different steel grades, which are then automatically executed by the intelligent control unit 5.

[0086] In addition, considering that this device operates under high pressure conditions above 1.8 MPa, all high-pressure pipeline connections of the device adopt metal hard-seal flange structures, and the sealing surface material is selected as hard alloy to solve the problem of easy leakage of conventional seals under high pressure and ensure the reliability of long-term sealing.

[0087] The device described in this invention adopts a modular steel structure base design, with all components integrated on a rigid base. After arriving at the site, it only needs to be connected to the existing pipeline via flanges and connected to the power and signal lines. This facilitates transportation, installation, and rapid placement and commissioning in the limited space of the converter workshop, resulting in a short installation and commissioning cycle and minimal impact on production.

[0088] Through the above specific embodiments, this invention achieves a significant increase in bottom-blowing gas supply pressure by utilizing end-point pressurization technology without modifying the plant's pipeline network. This effectively solves the problem of insufficient bottom-blowing stirring intensity in existing converters and features a compact structure, precise control, and high safety and reliability.

[0089] The embodiments of the present invention have been described in detail above. However, those skilled in the art can make several improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A gas supply pressurization device for enhancing the bottom blowing effect of a converter, integrated into the pipeline between the end of the gas source pipe (1) of the converter bottom blowing gas supply system and the bottom gas supply element (8), wherein a pre-filter (2) is provided on the gas source pipe (1), characterized in that: It includes a pressurization unit (3), an intelligent control unit (5), a safety interlock unit (6), and a quick switching unit (7). The pressurization unit (3) is physically connected in series in the main gas supply pipeline to receive low-pressure gas from the gas source and raise its pressure to the target high pressure. The pressurization unit (3) includes a two-stage pressurization module, which includes a first-stage scroll compressor (3-1), an interstage cooler, a gas-water separator (3-3), and a second-stage hydraulic coupling booster pump (3-2) connected in series along the gas flow direction through a high-pressure alloy steel pipe. The first-stage scroll compressor (3-1) initially raises the gas source pressure from 0.6-0.8 MPa to 1.2-1.5 MPa. After being cooled by the interstage cooler and dehydrated by the gas-water separator (3-3), the gas enters the second-stage hydraulic coupling booster pump (3-2) and is finally boosted and stably output to the target high pressure of 1.8-2.5 MPa. The intelligent control unit (5) is connected to the pressurization unit (3), safety interlock unit (6), fast switching unit (7), and converter main control system via signal lines. It is used to receive process parameters and output control commands. The intelligent control unit (5) includes a PLC controller (5-1), a pressure / flow sensor (5-3) connected to the PLC controller (5-1), and an HMI (human-machine interface) (5-2). The pressure / flow sensor (5-3) is installed at the inlet, interstage position, and outlet of the pressurization unit (3) to collect pressure / flow data in real time. Flow data; The PLC controller (5-1) is also connected to the first-stage scroll compressor (3-1) and the second-stage hydraulic coupling booster pump (3-2). The PLC controller (5-1) has a built-in adaptive PID control algorithm. This algorithm sets the target pressure value according to the received carbon content, temperature and blowing stage of the molten steel in the converter pool, and dynamically adjusts the speed of the variable frequency motor of the first-stage scroll compressor (3-1) and the servo oil pressure of the second-stage hydraulic coupling booster pump (3-2) to achieve precise closed-loop control of the output gas pressure and flow rate; The safety interlock unit (6) is connected to the output pipeline of the pressurization unit (3) to monitor pressure over-limit and perform safety actions; the safety interlock unit (6) includes a pressure relief branch (6-5) connected in parallel to the main gas supply pipeline, and a backup bypass (6-4) also connected in parallel to the main gas supply pipeline. The backup bypass (6-4) cooperates with the pressure relief branch (6-5) through a three-way ball valve (6-3). The pressure relief branch (6-5) is responsible for over-pressure relief, and the backup bypass (6-4) is responsible for fault supply protection; mechanical safety devices are installed sequentially on the pressure relief branch (6-5). The full valve (6-1) and the electromagnetic pilot-operated pressure relief valve (6-2), the mechanical safety valve (6-1), the electromagnetic pilot-operated pressure relief valve (6-2), and the three-way ball valve (6-3) are all connected to the PLC controller (5-1). When the pressure / flow sensor (5-3) detects that the outlet pressure exceeds 2.6 MPa or is lower than 1.6 MPa, the PLC controller (5-1) immediately triggers the electromagnetic pilot-operated pressure relief valve (6-2) to open and relieve pressure, and at the same time controls the three-way ball valve (6-3) to switch to the standby bypass to ensure continuous gas supply to the gas supply element at the bottom of the furnace. A quick-switching unit (7) is integrated into the pipeline system to achieve uninterrupted switching between pressurization mode and bypass mode. The quick-switching unit (7) includes a main electric butterfly valve (7-1) and a bypass electric butterfly valve (7-2) connected in parallel. A three-way ball valve (6-3) is used to select the pressurization branch (7-4) or the bypass branch (7-3). The main electric butterfly valve (7-1) is located on the pressurization branch (7-4), which is also connected in parallel to the main gas supply pipeline. The bypass electric butterfly valve (7-2) is located on the bypass branch (7-3), which is connected to the standby bypass (6-4). The three-way ball valve (6-3) is located at the connection between the pressurization branch (7-4) and the standby bypass (6-4). The main electric butterfly valve (7-1) and the bypass electric butterfly valve (7-2) are connected to the PLC controller (5-1) of the intelligent control unit (5). In normal pressurization mode, the main electric butterfly valve (7-1) is open, the bypass electric butterfly valve (7-2) is closed, and the three-way ball valve (6-3) is switched to connect with the pressurization unit (3), and the gas flows through the pressurization unit (3). When it is necessary to switch to the bypass, the intelligent control unit (5) issues a switching command or the safety interlock is triggered, the main electric butterfly valve (7-1) is closed, the bypass electric butterfly valve (7-2) is opened simultaneously, and the three-way ball valve (6-3) is switched to connect with the bypass, so as to realize the seamless switching of the gas supply path.

2. The gas supply and pressurization device for enhancing the bottom blowing effect of a converter according to claim 1, characterized in that: The interstage cooler adopts an annular sleeve water-cooled structure. The cooling water inlet is equipped with an electric regulating valve, which is connected to the PLC controller (5-1). The opening degree of the electric regulating valve is adjusted by the PLC controller (5-1) according to the interstage gas temperature signal to ensure that the gas temperature entering the second-stage hydraulic coupling booster pump (3-2) is below 50℃.

3. The gas supply and pressurization device for enhancing the bottom blowing effect of a converter according to claim 2, characterized in that: The hydraulic circuit system of the second-stage hydraulic coupling booster pump (3-2) integrates an oil temperature cooler and a precision oil filter to ensure the stability and reliability of the hydraulic system, thereby guaranteeing the extreme stability of the output pressure, with a pressure fluctuation range of no more than ±0.05Mpa.

4. The gas supply and pressurization device for enhancing the bottom blowing effect of a converter according to claim 2, characterized in that: The HMI (5-2) provides a pressure-flow setting curve template library. Operators can select a preset or custom "pressure-blowing time" curve according to the smelting process requirements of different steel grades, which will be automatically executed by the intelligent control unit (5).

5. The gas supply and pressurization device for enhancing the bottom blowing effect of a converter according to claim 1, characterized in that: All high-pressure pipeline connections use metal hard-seal flanges with hard alloy sealing surfaces to ensure long-term sealing reliability under high-pressure conditions above 1.8 MPa.

6. A gas supply pressurization device for enhancing the bottom blowing effect of a converter according to any one of claims 1-5, characterized in that: The adaptive PID control algorithm runs inside the PLC controller (5-1), and automatically adjusts the proportional coefficient K p , integral coefficient K i and differential coefficient K d of the PID controller according to different stages (such as pre-blowing stage, mid-blowing stage and end-blowing stage) of the converter blowing and the molten pool state (carbon content, temperature) to adapt to different requirements for the response speed and stability of the gas flow under different working conditions, and specifically includes three logic modules: a process parameter preprocessing module, a parameter self-tuning PID operation module and an execution action module. Process parameter preprocessing module: Receives real-time carbon content data uploaded by the converter main control system. Real-time temperature Given the current blowing time t, the basic target pressure setpoint for the current moment is calculated based on the "pressure-blowing time" curve template preset in the HMI (5-2). ， Based on the real-time molten pool status Fine-tuning is performed; when the carbon content is detected to be higher than expected, the algorithm determines that the decarbonization rate needs to be accelerated, automatically increasing the target pressure value to increase the stirring kinetic energy. Example of formula correction: ， in SP target The target pressure value; C set , T set These are the carbon content setting value and the temperature setting value, respectively. K c , K t This is a correction factor; Parameter self-tuning PID calculation module: Based on the characteristic values ​​of the blowing stage, it calls the corresponding PID parameter group to perform calculations and outputs the control quantity u(t); Action Module: The PLC controller (5-1) sends frequency adjustment commands to the inverter of the first-stage scroll compressor (3-1) and current signals to the electro-hydraulic servo valve of the second-stage hydraulic coupling booster pump (3-2) based on the control quantity output by the self-tuning PID calculation, thereby realizing two-stage coordinated control.

7. The gas supply and pressurization device for enhancing the bottom blowing effect of a converter according to claim 6, characterized in that: In the parameter self-tuning PID calculation module, "calling the corresponding PID parameter set for calculation based on the characteristic values ​​of the blowing stage" means that since the different stages of converter blowing include the early blowing stage, the middle blowing stage, and the end blowing stage, the parameter sets for the early blowing stage, the middle blowing stage, and the end blowing stage are called respectively. The specific implementation steps are as follows: Step 1: Pre-refining stage – Quick response mode Operating characteristics: The molten pool temperature is relatively low, and the oxidation of ferrosilicon and manganese is intense, requiring a large bottom-blowing flow rate for rapid slag formation, but with low requirements for pressure accuracy. PID parameter setting strategy: PLC calls "early parameter group", parameter instance: set proportional coefficient K p Large, integral coefficient K i Small, differential coefficient K d Moderate, this setting can improve the response speed of the system, so that the first stage scroll compressor (3-1) and the second stage hydraulic coupling type booster pump (3-2) can quickly reach high speed output to meet the initial large flow demand; Step Two: Mid-stage of refining – Stabilization and Adjustment Mode Operating conditions: The carbon-oxygen reaction is intense, and the temperature of the molten pool rises. At this time, it is necessary to maintain a moderate stirring intensity and avoid large pressure fluctuations that could cause splashing. PID parameter tuning strategy: The PLC controller (5-1) automatically switches to the "intermediate parameter group" based on the time signal or the carbon-oxygen reaction rate signal. Parameter example: Appropriately reduce K. p Increase K i This adjustment suppressed overshoot and ensured a smooth transition of gas supply pressure within the range of 1.8-2.5 MPa. Step 3: End of Blowing Process – High-Precision Constant Temperature and Pressure Mode Operating conditions: Near the end point, the carbon content of the molten steel is low and the oxygen content is high, requiring extremely high uniformity of bottom blowing agitation in order to reduce the carbon-oxygen product. PID parameter tuning strategy: PLC switches to "Endpoint parameter group". Parameter example: using a smaller K. p and larger K i And introduce the differential coefficient K d Predictive control is performed, and the algorithm is extremely sensitive to pressure deviation. It can accurately control the second-stage hydraulic coupling booster pump (3-2) to strictly control the outlet pressure fluctuation within the range of ±0.05MPa.

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