Wind pressure stabilization control method and device for side-blowing smelting production system

Abstract

The present invention provides a method for controlling the pressure stabilization of wind in a side-blowing smelting production system, comprising: monitoring the pressure in the gas supply pipeline of the side-blowing smelting production system, and when the pressure value is within a preset range, adjusting the opening of a first regulating valve provided on the gas supply pipeline, closing the second regulating valve on the gas supply pipeline, so that the pressure value approaches and is maintained at a first preset value; when the pressure value is greater than the preset range, adjusting the opening of the first regulating valve and the second regulating valve, so that the pressure value approaches and is maintained at a second preset value; wherein the preset range includes the first preset value and the second preset value. By using the above-mentioned method for controlling the pressure stabilization of wind in a side-blowing smelting production system and the device thereof, the maintenance and replacement of the valve core of the valve can be effectively reduced, thereby reducing the maintenance cost.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgical automation control, and more specifically, to a method and device for controlling wind pressure stabilization in a side-blowing smelting production system. Background Art

[0002] In the prior art, in a metallurgical production system using a side-blown furnace as a smelting furnace, the oxygen-enriched air supply concentration is generally required to be around 60-85%. The oxygen-enriched concentration is usually controlled by mixing compressed air and industrial oxygen at different flow rates. The compressed air is provided by a centrifugal air compressor located in the blower room, and the industrial oxygen is provided by an oxygen production station with a concentration of 99.6% pure oxygen.

[0003] The side-blowing smelting furnace adopts the method of counter-blowing by multi-functional multi-channel spray guns on both sides of the side walls. The oxygen-enriched air required for smelting is blown in from the spray guns on both sides of the side outlet furnace. During normal production, the operating air outlets account for about 40-70% of the total.

[0004] When stopping the material during the production process, in order to extend the service life of the side-blowing furnace and the spray gun, it is necessary to quickly plug all the air holes in use, and then close the valves on the smelting oxygen supply and air supply (compressed air) pipelines. However, since the oxygen compressor and air compressor units cannot be shut down at any time, and the pipeline network is not allowed to be pressurized to the point where the unit surges, it is necessary to adjust the air pressure in the pipeline network.

[0005] The existing technical solutions have two main disadvantages:

[0006] 1. Due to the large pressure difference between the front and rear of the vent pressure regulating valve, the performance, adaptability and life of the valve are greatly affected, and there will be problems such as blocked logistics, cavitation, high noise level and vibration: there will also be wear and tear on the valve body and valve core and damage from cavitation, resulting in failure of the valve itself or poor performance, and calibration of the auxiliary instruments.

[0007] 2. When the venting pressure regulating valve is in the venting state, when oxygen is needed to put in materials again, it takes a long time for the system to increase the pressure to meet the production needs of the smelting furnace, and it cannot meet the production needs of the smelting furnace at any time.

[0008] Therefore, there is an urgent need for a method and device for controlling air pressure stabilization, which is designed with a multi-stage regulating valve on the air supply pipeline. Starting from the process of plugging the air eye, the valve positioner arranged on the regulating valve automatically adjusts the pressure in the pipeline according to the control signal of the controller to prevent the oxygen compressor and the air compressor from being "stuck" into the surge zone. Summary of the invention

[0009] In view of the above problems, an object of the present invention is to provide a method and device for controlling wind pressure stabilization in a side-blowing smelting production system to solve the above problems.

[0010] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a method for controlling wind pressure stabilization in a side-blowing smelting production system, comprising:

[0011] Monitor the pressure in the gas supply pipeline of the side-blowing smelting production system, and when the pressure value is within a preset range, adjust the opening of a first regulating valve on the gas supply pipeline, close the second regulating valve on the gas supply pipeline, so that the pressure value approaches and is maintained at a first preset value;

[0012] When the pressure value is greater than the preset range, adjusting the openings of the first regulating valve and the second regulating valve to make the pressure value approach and maintain at a second preset value;

[0013] The preset range includes the first preset value and the second preset value.

[0014] In addition, an optimized solution is that the preset range is 0-0.4MPa, the first preset value is 0.35MPa, and the second preset value is 0.3MPa.

[0015] In addition, the optimized solution is that the openings of the first regulating valve and the second regulating valve are automatically controlled by a controller, and the controller obtains the pressure value in the gas supply pipeline via a pressure transmitter and performs the following operations:

[0016] When the pressure value is greater than a preset value, the controller increases the opening of the first regulating valve and / or the second regulating valve;

[0017] When the pressure value is less than a preset value, the controller reduces the opening of the first regulating valve and / or the second regulating valve.

[0018] In addition, the optimized solution is that the controller controls the first regulating valve and the second regulating valve in a split-range control manner, and inputs a 4-20 mA control signal to the first regulating valve and the second regulating valve;

[0019] The first valve positioner provided on the first regulating valve adjusts the opening of the first regulating valve after receiving the control signal, and feeds back the opening of the first regulating valve to the controller;

[0020] The second valve positioner provided on the second regulating valve adjusts the opening of the second regulating valve after receiving the control signal, and feeds back the opening of the second regulating valve to the controller; wherein

[0021] The working signal of the first valve positioner is set to 4-12 mA, and the working signal of the second valve positioner is set to 12-20 mA.

[0022] In order to achieve the above object, in a second aspect, the present invention provides a wind pressure stabilization control device for a side-blowing smelting production system, which is used to execute the wind pressure stabilization control method for the side-blowing smelting production system, comprising:

[0023] A first venting pipeline, one end of which is connected to the gas supply pipeline and is provided with a first regulating valve;

[0024] A second venting pipeline, one end of which is connected to the gas supply pipeline and is provided with a second regulating valve, and the diameter of the second venting pipeline is larger than the diameter of the first venting pipeline;

[0025] A controller, one end of which is connected to the gas supply pipeline via a pressure transmitter to obtain the gas pressure in the gas supply pipeline, and the other end of which is connected to the first regulating valve and the second regulating valve to control the opening of the first regulating valve and the second regulating valve according to the wind pressure stabilization control method for the side-blowing smelting production system as described in any of the above items.

[0026] In addition, an optimized solution is that the first vent pipeline and the second vent pipeline are arranged in parallel on the gas supply pipeline.

[0027] In addition, the optimized solution is that a first valve positioner is provided on the first regulating valve, which is used to receive a control signal from the controller and adjust the opening of the first regulating valve according to the control signal;

[0028] The second regulating valve is provided with a second valve positioner for receiving a control signal from the controller and adjusting the opening of the second regulating valve according to the control signal.

[0029] In addition, an optimized solution is that the control signal output by the controller is 4-20 mA, the working signal of the first valve positioner is 4-12 mA, and the working signal of the second valve positioner is 12-20 mA.

[0030] According to the above description and practice, the side-blowing smelting production system air pressure stabilization control method and device described in the present invention adopts split-range control, by arranging a regulating valve in the air supply pipeline and controlling the valve positioner of the regulating valve, and adjusting the opening of the regulating valve by controlling the valve positioner through a controller, so that the device can promptly respond to problems such as blocked logistics, cavitation, high noise levels and vibration in the prior art, avoid wear of the valve body and valve core, and damage of cavitation, effectively reduce the maintenance and replacement of the valve core of the valve, thereby reducing maintenance costs.

[0031] In order to achieve the above and related purposes, one or more aspects of the present invention include features that will be described in detail later and are particularly pointed out in the claims. The following description and the accompanying drawings describe some exemplary aspects of the present invention in detail. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all of these aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] By referring to the following description and claims in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more apparent and easier to understand. In the accompanying drawings:

[0033] Figure 1 A flow chart showing a method for controlling wind pressure stabilization in a side-blowing smelting production system according to the present invention; and

[0034] Figure 2 A block diagram of a wind pressure stabilizing control device for a side-blowing smelting production system according to the present invention is shown.

[0035] The same reference numerals throughout the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0036] In the following description, for the purpose of illustration, in order to provide a comprehensive understanding of one or more embodiments, many specific details are set forth. However, it is apparent that these embodiments may also be implemented without these specific details. In other examples, for ease of describing one or more embodiments, known structures and devices are shown in the form of block diagrams.

[0037] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0038] The present invention designs two-stage pressure-stabilizing venting pipelines on the oxygen supply and air supply pipelines of the pipeline network, and each pipeline is provided with a regulating valve. Starting from the process of plugging the air eye, the two-stage pressure-stabilizing venting pipeline automatically adjusts according to the set pressure to keep the pipeline pressure stable, thereby preventing the oxygen compressor and the air compressor from being "stifled" into the surge zone.

[0039] Figure 1 The flow chart of the wind pressure stabilization control method for the side-blowing smelting production system according to the present invention is shown. In this embodiment, the oxygen supply pipeline is used as an example for explanation, and the scheme is also applicable to pipelines supplying other gases.

[0040] like Figure 1 As shown, the wind pressure stabilization control method for the side-blowing smelting production system provided by the present invention comprises:

[0041] Monitor the pressure in the gas supply pipeline of the side-blowing smelting production system, and when the pressure value is within a preset range, adjust the opening of a first regulating valve on the gas supply pipeline, and close the second regulating valve on the gas supply pipeline, so that the pressure value approaches and is maintained at a first preset value;

[0042] When the pressure value is greater than the preset range, adjusting the openings of the first regulating valve and the second regulating valve so that the pressure value approaches and is maintained at the second preset value;

[0043] The preset range includes a first preset value and a second preset value.

[0044] Specifically, the preset range is 0-0.4MPa. When the oxygen supply pressure is within the preset range, the system produces normally. Among them, the first preset value is 0.35MPa and the second preset value is 0.3MPa. Here, since the opening of the first regulating valve and the second regulating valve are adjusted at the same time, the pressure in the air supply pipeline decreases faster. Therefore, the second preset value is lower than the first preset value.

[0045] During the production process, if the valve on the oxygen supply pipeline is closed, the oxygen compressor unit cannot be shut down at any time, which makes it easy for the oxygen compressor to be "stifled" into the surge zone. Therefore, it is necessary to keep the total oxygen supply pipeline pressure stable to ensure normal production. Therefore, it is necessary to adjust the pressure in the oxygen supply pipeline by the above method. Specifically, the opening of the first regulating valve and the second regulating valve is automatically controlled by the controller. The controller obtains the pressure value in the gas supply pipeline via the pressure transmitter and performs the following operations: when the pressure value is greater than the preset value, the controller increases the opening of the first regulating valve and / or the second regulating valve; when the pressure value is less than the preset value, the controller decreases the opening of the first regulating valve and / or the second regulating valve. Thereby, the pressure in the gas supply pipeline is automatically adjusted to ensure the normal operation of production. In the event of an accident, when the pressure in the oxygen supply pipeline drops or increases suddenly, the oxygen supply pressure can also be adjusted quickly and effectively, effectively protecting the valves on the pipeline, avoiding the wear of the valve body and the valve core, and the damage of cavitation, effectively reducing the maintenance and replacement of the valve core of the valve, thereby reducing the maintenance cost.

[0046] Specifically, the controller controls the first regulating valve and the second regulating valve in a split-range control manner, and inputs a 4-20mA control signal to the first regulating valve and the second regulating valve; the first valve positioner arranged on the first regulating valve adjusts the opening of the first regulating valve after receiving the control signal, and feeds back the opening of the first regulating valve to the controller; the second valve positioner arranged on the second regulating valve adjusts the opening of the second regulating valve after receiving the control signal, and feeds back the opening of the second regulating valve to the controller; wherein the working signal of the first valve positioner is set to 4-12mA, and the working signal of the second valve positioner is set to 12-20mA. When in use, the maximum value of the valve pressure adjustment of the first regulating valve and the second regulating valve is 0.1MPa, so that the pressure adjustment process is stable, which can effectively avoid high pressure from absorbing a large amount of oxygen supply system energy during the process of reducing pressure, so that when the production system needs oxygen supply again, it can increase the pressure in a very short time and meet the production needs of the smelting furnace, thereby improving production efficiency.

[0047] It should be specially noted that the above data (including the preset range, the first preset value, the second preset value, the control signal, and the specific range of the control signal) only represent the numerical values ​​of the embodiments involved in the present invention. In other embodiments, the specific numerical values ​​of the above data may also change according to different working conditions.

[0048] More specifically, according to the actual situation of the operation site, a third regulating valve and a third valve positioner adapted to the third regulating valve may be provided, and so on. In the present invention, only two regulating valves are described to clearly and concisely illustrate the present invention.

[0049] Figure 2 A block diagram of a wind pressure stabilizing control device for a side-blowing smelting production system according to the present invention is shown.

[0050] like Figure 2 As shown, in order to achieve the above-mentioned purpose, the present invention provides a wind pressure stabilization control device for a side-blowing smelting production system, which is used to execute the above-mentioned wind pressure stabilization control method for a side-blowing smelting production system, including: a first venting pipeline, a second venting pipeline and a controller.

[0051] One end of the first vent pipeline is connected to the gas supply pipeline, on which a first regulating valve is provided for regulating the gas pressure in the gas supply pipeline. One end of the second vent pipeline is connected to the gas supply pipeline, on which a second regulating valve is provided. The diameter of the second vent pipeline is larger than that of the first vent pipeline. The second vent pipeline cooperates with the first vent pipeline to more quickly regulate the gas pressure in the gas supply pipeline.

[0052] Specifically, when the air pressure in the gas supply pipeline only needs to be vented a small amount, only the first regulating valve on the first vent pipeline needs to be adjusted to meet the requirement and vent a small amount of gas; when the air pressure in the gas supply pipeline reaches a certain intensity and a small amount of venting cannot meet the requirement and may cause a safety accident, the corresponding regulating valves on the first vent pipeline and the second vent pipeline are adjusted at the same time to vent a large amount of air pressure in the gas supply pipeline to avoid safety accidents. From the above description, it can be seen that the first vent pipeline vents less gas, so the diameter of the first vent pipeline is smaller. When the second vent pipeline is started, a large amount of air pressure needs to be vented. Therefore, the diameter of the second vent pipeline is larger than the diameter of the first vent pipeline. At the same time, from the perspective of energy conservation and environmental protection, during use, the gas in the gas supply pipeline is fully utilized as much as possible to reduce unnecessary waste, so the diameter of the second vent pipeline is larger than the diameter of the first vent pipeline.

[0053] One end of the controller is connected to the gas supply pipeline via a pressure transmitter to obtain the air pressure in the gas supply pipeline, and the other end is connected to the first regulating valve and the second regulating valve to control the opening of the first regulating valve and the second regulating valve according to any of the above-mentioned side-blowing smelting production systems using wind pressure stabilization control methods.

[0054] Specifically, the first venting pipeline and the second venting pipeline are arranged in parallel on the gas supply pipeline to transmit the gas. The gas pressure in the gas supply pipeline can be released more efficiently and quickly by being arranged in parallel.

[0055] Specifically, the first regulating valve is provided with a first valve positioner for receiving a control signal from a controller and adjusting the opening of the first regulating valve according to the control signal; the second regulating valve is provided with a second valve positioner for receiving a control signal from the controller and adjusting the opening of the second regulating valve according to the control signal. By separately providing a valve positioner on each regulating valve, the controller can better adaptably adjust the opening and closing degrees of different regulating valves on different pipelines, ensuring that the air pressure in the gas supply pipeline is not excessively wasted, and at the same time, ensuring the safe use of the gas supply pipeline.

[0056] Specifically, the control signal output by the controller is 4-20mA, the working signal of the first valve positioner is 4-12mA, and the working signal of the second valve positioner is 12-20mA. Of course, the signal distribution range and specific values ​​of the valve positioners on the regulating valves will be different depending on the number of regulating valves. By setting the working signal range of the two valve positioners, the controller can independently control the two valve positioners, thereby achieving precise control of the opening of the two regulating valves.

[0057] A further optimization is to install an air-release muffler at the exhaust port of the air defense pipeline to play a role in silencing, which is used to reduce exhaust pulsation and reduce exhaust noise as much as possible. The solenoid valve makes a loud noise when exhausting, especially when there are many solenoid valves. Installing a muffler can effectively reduce noise. At the same time, it can prevent fine particles such as dust in the environment from entering the solenoid valve. Otherwise, particles entering the solenoid valve will cause the movement of the solenoid valve core to be blocked, thereby reducing the service life of the solenoid valve.

[0058] Next, the wind pressure stabilization control method and the combined device for the actual side-blowing smelting production system of the present invention are further explained by taking smelting oxygen as an example.

[0059] The side-blown furnace smelting oxygen supply main pipe (99.6% pure oxygen from the oxygen station, about 0.35MPa) has many uses for oxygen of different pressure levels. The oxygen supply pressure to the primary air spray gun of the side-blown furnace is about 150KPa. Therefore, a pressure reducer is installed before mixing oxygen (to reduce the oxygen supply pressure from about 0.35MPa to about 0.2MPa). The oxygen supply pressure for other purposes (such as to the combustion burner of the side-blown furnace) is about 0.35MPa.

[0060] Working principle: The pressure value of the gas in the gas supply pipeline is obtained according to the pressure transmitter installed on the gas supply pipeline, and the measured pressure value is uploaded to the controller. The valve positioner receives the output signal of the controller and controls the regulating valve on the gas supply pipeline according to the output signal to adjust the pressure value in the pipeline.

[0061] In this embodiment, the first regulating valve is a primary pressure-stabilizing and venting regulating valve, and the second regulating valve is a secondary pressure-stabilizing and venting regulating valve.

[0062] When in use, the signal distribution range of the valve positioner on the first-level pressure-stabilizing and venting regulating valve is 4-12mA, and the electrical signal distribution range of the valve positioner on the second-level pressure-stabilizing and venting regulating valve is 12-20mA. The flow characteristics of the two groups of pressure-stabilizing and venting regulating valves are equal percentages and have the same working mode. The flow volume of the first-level pressure-stabilizing and venting regulating valve is 80 after calculation, and the flow volume of the second-level pressure-stabilizing and venting regulating valve is 20 after calculation. In the prior art, the adjustable ratio of the two pressure-stabilizing and venting regulating valves is 50:1, and the flow capacity C main pipeline min = 80 / 50 = 1.6, C branch pipeline min = 20 / 50 = 0.4. In the present invention, after the two pressure-stabilizing and venting regulating valves are used in parallel, the flow capacity range is 0.4-100, and the adjustable ratio becomes 100:0.4 = 250. Compared with a single regulating valve, the adjustable ratio after split-range control is 5 times the original.

[0063] Through graded regulation, the existing technology effectively solves the problems of wear and cavitation of valve body and valve core, failure or performance degradation of valve itself, calibration drift of auxiliary instruments, pipeline fatigue or hearing loss of nearby workers. At the same time, in response to emergencies, the valve positioner can be adjusted in time and effectively to prevent excessive waste of gas in the pipeline, and when production resumes, production needs can be quickly met.

[0064] According to the above description and practice, the wind pressure stabilization control method and device for the side-blowing smelting production system of the present invention adopts split-range control.

[0065] By arranging a regulating valve in the gas supply pipeline and controlling a valve positioner of the regulating valve, and controlling the valve positioner through a controller to adjust the opening of the regulating valve, the device can promptly respond to problems such as blocked logistics, cavitation, high noise levels and vibrations in the prior art, avoid wear of the valve body and valve core, and damage from cavitation, effectively reduce the maintenance and replacement of the valve core of the valve, and thus reduce maintenance costs.

[0066] As above Figure 1 and Figure 2 The wind pressure stabilization control method and device for the side-blowing smelting production system according to the present invention are described by way of example. However, those skilled in the art should understand that various improvements can be made to the wind pressure stabilization control method and device for the side-blowing smelting production system proposed by the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the attached claims.

Claims

1. A method for controlling wind pressure stabilization in a side-blowing smelting production system, comprising: Monitor the pressure in the gas supply pipeline of the side-blowing smelting production system, and when the pressure value is within a preset range, adjust the opening of a first regulating valve on the gas supply pipeline, close the second regulating valve on the gas supply pipeline, so that the pressure value approaches and is maintained at a first preset value; When the pressure value is greater than the preset range, adjusting the openings of the first regulating valve and the second regulating valve to make the pressure value approach and maintain at a second preset value; Wherein, the preset range includes the first preset value and the second preset value, and the second preset value is lower than the first preset value; The openings of the first regulating valve and the second regulating valve are automatically controlled by a controller, and the controller obtains the pressure value in the gas supply pipeline via a pressure transmitter; The controller controls the first regulating valve and the second regulating valve in a split-range control manner, and inputs a 4-20 mA control signal to the first regulating valve and the second regulating valve; The first valve positioner provided on the first regulating valve adjusts the opening of the first regulating valve after receiving the control signal, and feeds back the opening of the first regulating valve to the controller; The second valve positioner provided on the second regulating valve adjusts the opening of the second regulating valve after receiving the control signal, and feeds back the opening of the second regulating valve to the controller; wherein The working signal of the first valve positioner is set to 4-12 mA, and the working signal of the second valve positioner is set to 12-20 mA.

2. The method for controlling the wind pressure stabilization of the side-blowing smelting production system according to claim 1, characterized in that: The preset range is 0-0.4 MPa, the first preset value is 0.35 MPa, and the second preset value is 0.3 MPa.

3. A wind pressure stabilization control device for a side-blowing smelting production system, used to execute the wind pressure stabilization control method for a side-blowing smelting production system according to any one of claims 1 to 2, characterized in that: include: A first venting pipeline, one end of which is connected to the gas supply pipeline and is provided with a first regulating valve; A second venting pipeline, one end of which is connected to the gas supply pipeline and is provided with a second regulating valve, and the diameter of the second venting pipeline is larger than the diameter of the first venting pipeline; A controller, one end of which is connected to the gas supply pipeline via a pressure transmitter to obtain the gas pressure in the gas supply pipeline, and the other end of which is connected to the first regulating valve and the second regulating valve to control the opening of the first regulating valve and the second regulating valve according to the wind pressure stabilization control method for the side-blowing smelting production system as described in any one of claims 1-2.

4. The wind pressure stabilizing control device for the side-blowing smelting production system according to claim 3, characterized in that: The first vent pipeline and the second vent pipeline are arranged in parallel on the gas supply pipeline.

Images