Method and system for adjusting compressed air pipe network of iron and steel plant

Abstract

The invention discloses an iron and steel plant compressed air pipe network adjusting method and system, and relates to the technical field of compressed air dispatching. The method comprises the steps that the running current of an air compressor in an external air compression station and the pressure value and the flow value in an external input branch pipe are obtained in real time; and the operation state of the external air compression station is judged according to the operation current, the pressure value and the flow value, if the operation state is abnormal, the internal adjusting air compression station is started, and the supply amount of the internal adjusting air compression station to the compressed air pipe network is dynamically adjusted according to the change amount of the flow value. According to the system for rapidly adjusting the compressed air pipe network of the iron and steel plant, the external air compression station is introduced to supply air to the iron and steel plant on the basis of the original compressed air pipe network of the iron and steel plant, and a large amount of cost for self-building air compression stations is saved; abnormity of the external air compression station can be found in the first time, an alarm signal is generated and automatically processed, and safety accidents are avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressed air dispatching, and in particular relates to a method and system for regulating a compressed air pipe network in a steel plant. Background Art

[0002] A stable supply of compressed air is crucial to the production efficiency and safety of steel plants. Changes in the air supply flow at the air compressor station, such as a sudden short supply or interruption, can affect the solidification of molten iron in blast furnaces and molten steel in converters, potentially causing major production accidents. To ensure safe and stable production within steel plants, timely adjustments to internal air compressor stations are necessary to increase supply or adjust flow, minimize losses caused by emergencies, and ensure accurate, swift, and effective emergency response.

[0003] Large steel mills all build their own internal air compressor stations to supply in-plant production, which has high production costs. In addition, the pressure regulation of the internal air compressor outlet pipeline is adjusted independently by each air compressor, and the compressed air pipeline system cannot be uniformly adjusted. This makes the compressed air pressure in the pipeline system unstable, affecting subsequent production. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: after an external air compressor station is connected to the internal compressed air network of a steel plant, when the supply of the external air compressor station fluctuates or stops, how to achieve rapid regulation of the compressed air flow in the internal compressed air network to ensure the production needs of various plant areas of the steel plant.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] In a first aspect, the present invention provides a method for regulating a compressed air network in a steel plant, comprising the following steps:

[0007] Obtain the operating current of the air compressor in the external air compression station and the pressure and flow values ​​in the external input branch pipe in real time;

[0008] The operating status of the external air compressor station is judged according to the operating current, pressure value and flow value. If the operating status is abnormal, the internal regulating air compressor station is started, and the supply volume of the internal regulating air compressor station to the compressed air pipeline network is dynamically adjusted according to the change in the flow value.

[0009] The method to judge the operating status of the external air compressor station is:

[0010] When the pressure values ​​of at least two external input branches are detected to be lower than the pressure threshold, it indicates that the external air compressor station is operating abnormally and a pressure abnormality alarm signal is issued;

[0011] When it is detected that the sum of the flow values ​​of all input branches decreases by more than the flow threshold, it indicates that the external air compressor station is operating abnormally and a flow abnormality alarm signal is issued;

[0012] When it is detected that the operating current of the air compressor of the external air compressor station is lower than the current threshold, it indicates that the operating state of the external air compressor station is abnormal, and a current abnormality alarm signal is issued.

[0013] When at least one of the pressure abnormality alarm signal, the flow abnormality alarm signal and the current abnormality alarm signal is received, the internal regulating air compression station is started.

[0014] The internal regulating air compressor station includes a variable frequency screw air compressor and several centrifugal air compressors. The variable frequency screw air compressor is used for flow regulation when the input flow in the pipeline network fluctuates within a small range, and the centrifugal air compressor is used for flow regulation when the supply volume of the external air compressor station fluctuates within a large range.

[0015] The method of dynamically adjusting the supply volume of the internal regulating air compressor station to the compressed air network according to the change in flow value is as follows:

[0016] When the decrease in flow rate is detected to be greater than the flow fluctuation threshold and less than 7680m 3 / h, start the variable frequency screw air compressor of the internal regulating air compressor station to buffer the reduced supply of the external air compressor station; when the variable frequency screw air compressor reaches the maximum supply, when the flow value is detected to decrease by 15000 m 3 / h, a centrifugal air compressor is turned on to buffer the reduced supply from the external air compression station until the flow value in the input branch pipe no longer decreases.

[0017] In a second aspect, the present invention provides a compressed air pipe network regulation system for a steel plant, comprising:

[0018] Internal regulating air compressor station, connected to the internal compressed air network;

[0019] The external air compression station is connected to the internal compressed air network through several external input branches, each of which is equipped with an inlet configuration valve, a monitoring unit and an outlet configuration valve;

[0020] The main controller is respectively connected to the external air compression station, the internal regulating air compression station and the monitoring unit for communication, receives the operating current signal of the air compressor in the external air compression station in real time, receives the pressure value and flow value in the external input branch pipe measured by the monitoring unit in real time, and controls the supply amount of the internal regulating air compression station to the compressed air pipeline network according to the operating current, pressure value and flow value.

[0021] The monitoring unit includes a pressure sensor and a flow sensor. The pressure sensor collects the compressed air pressure value in the external input branch in real time and transmits it to the main controller. The flow sensor collects the compressed air flow value in the external input branch in real time and transmits it to the main controller. The sum of the flow rates of each external input branch is the output flow value of the external air compressor station.

[0022] The terminal gas-using plant area of ​​the internal compressed air network is provided with a pressure detection unit and a boosting unit. When the detected pressure value is lower than the required pressure value of the terminal gas-using plant area, the boosting unit is started.

[0023] The beneficial effects of the present invention are as follows: the system for rapid adjustment of the compressed air network of the steel plant of the present invention introduces an external air compressor station to supply air to the steel plant on the basis of the original compressed air network of the steel plant, which saves a lot of cost of building an air compressor station by itself, and introduces the compressed air supply as the surplus supply of the external air compressor station, which effectively avoids waste of resources; the present invention can detect the abnormality of the external air compressor station in the first time, generate an alarm signal, and automatically process and maintain the normal supply in the compressed air network, and dynamically adjust the supply of the internal air compressor station according to the detected pressure changes and flow changes in the pipeline, thereby ensuring the normal operation of each gas-consuming equipment in the system, avoiding the occurrence of safety accidents, saving resources, and increasing the efficiency of the steel plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Structural diagram of the compressed air pipe network regulation system for a steel plant according to the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0026] Example 1

[0027] refer to Figure 1 As shown, a method for regulating the compressed air network in a steel plant includes the following steps:

[0028] Obtain the operating current of the air compressor in the external air compressor station and the pressure and flow values ​​in the external input branch pipe in real time.

[0029] The operating status of the external air compressor station is judged according to the operating current, pressure value and flow value. If the operating status is abnormal, the internal regulating air compressor station is started, and the supply volume of the internal regulating air compressor station to the compressed air pipeline network is dynamically adjusted according to the change in the flow value.

[0030] In the figure, the 3# air compressor station is an internal regulation air compressor station, F11, F12, and F13 are inlet regulating valves, F1, F2, and F3 are inlet regulating valves, P1, P2, and P3 are pressure sensors, and L1, L2, and L3 are flow sensors.

[0031] In this embodiment, the internal compressed air network is connected to the external air compressor station via three external input branches and one backup input branch. Each external input branch is equipped with an inlet configuration valve, a monitoring unit, and an outlet configuration valve. The backup input branch is used when other external input branches require maintenance to ensure normal production.

[0032] Abnormal operating status of the external air compressor station includes: abnormal pressure, abnormal flow and abnormal operating current.

[0033] More specifically, pressure anomaly means: when the pressure values ​​of at least two external input branch pipes are lower than the pressure threshold, it indicates that the external air compressor station is operating abnormally and a pressure anomaly alarm signal is issued; when the pressure values ​​of two or more pressure sensors on the three external input branch pipes are lower than 0.57 MPa, it indicates that the external air compressor station is operating abnormally and a pressure anomaly alarm signal is issued;

[0034] More specifically, a flow anomaly means that when the sum of the flow values ​​of all input branches decreases by more than the flow threshold, it indicates that the external air compressor station is operating abnormally and a flow anomaly alarm signal is issued. In other words, if the total decrease in the flow values ​​L1+L2+L3 monitored by the flow sensors on the three input branches exceeds 7680m3 / h, it indicates that the external air compressor station is operating abnormally and a flow anomaly alarm signal is issued.

[0035] More specifically, current abnormality means: when the operating current of the air compressor of the external air compressor station is lower than the current threshold, it indicates that the operating status of the external air compressor station is abnormal, and a current abnormality alarm signal is issued; that is, the rated current of the external air compressor is 580A. When it is detected that the operating current of the air compressor of the external air compressor station is lower than 250A, it indicates that the operating status of the external air compressor station is abnormal, and a current abnormality alarm signal is issued.

[0036] The method of dynamically adjusting the supply volume of the internal regulating air compressor station to the compressed air network according to the change of the flow value is as follows: when the decrease of the flow value is detected to be greater than the flow fluctuation threshold and less than 7680m 3 / h, start the variable frequency screw air compressor of the internal regulating air compressor station to buffer the reduced supply of the external air compressor station; when the variable frequency screw air compressor reaches the maximum supply, it detects that the flow value decreases by 15000m 3 / h, start a centrifugal air compressor until the flow value in the input branch pipe no longer decreases.

[0037] Example 2

[0038] refer to Figure 1 As shown, a compressed air pipe network regulation system for a steel plant includes:

[0039] Internal regulating air compressor station, connected to the internal compressed air network;

[0040] The external air compression station is connected to the internal compressed air network through several external input branches, each of which is equipped with an inlet configuration valve, a monitoring unit and an outlet configuration valve;

[0041] The main controller is respectively connected to the external air compression station, the internal regulating air compression station and the monitoring unit for communication, receives the operating current signal of the air compressor in the external air compression station in real time, receives the pressure value and flow value in the external input branch pipe measured by the monitoring unit in real time, and controls the supply amount of the internal regulating air compression station to the compressed air pipeline network according to the operating current, pressure value and flow value.

[0042] The monitoring unit includes a pressure sensor and a flow sensor; the pressure sensor collects the compressed air pressure value in the external input branch in real time and transmits it to the main controller; the flow sensor collects the compressed air flow value in the external input branch in real time and transmits it to the main controller. The sum of the flow rates of each external input branch is the output flow rate of the external air compressor station.

[0043] The internal regulating air compressor station includes variable frequency screw air compressors and several centrifugal air compressors. The variable frequency screw air compressor supply capacity is 7680m 3 / h, used for flow regulation when the input flow in the pipe network fluctuates within a small range. The supply capacity of the centrifugal air compressor is 15000m 3 / h, used for flow regulation when the supply volume of the external air compressor station fluctuates widely, especially when the external air compressor station is shut down.

[0044] The compressed air provided by the external air compressor station is the surplus compressed air generated during the production process of the thermal power plant. The external air compressor station uses 2×45000Nm³ / h electric drive centrifugal air compressors and is equipped with 4×30000Nm 3 / h compression heat adsorption dryer (three in use and one in standby) and supporting electrical and thermal control equipment, with a normal supply capacity of approximately 90,000 m³ / h (accounting for approximately 45% of the steel plant's total gas supply).

[0045] The starting pressure of compressed air is 0.85MPa, and the connection point pressure is 0.746MPa, which meets the conditions for accessing the compressed air pipeline network of the steel plant and can ensure the connection point pressure requirements of users in various plant areas of the steel plant.

[0046] The internal compressed air network is equipped with a pressure detection unit and a booster unit (not shown) at the terminal gas-consuming plant. When the pressure of the compressed air at the terminal is detected to be lower than the production pressure requirement of the gas-consuming plant, the booster unit is activated to boost the air pressure at the terminal of the network, meeting the individual pressure requirements of the plant at the terminal, reducing the overall pressure of the compressed air network, and reducing overall production and operation energy consumption. For example, a centrifugal pipeline air booster is added to the coking plant air pipeline at the end of the steel plant's compressed air network to slightly boost the air pressure at the terminal of the network. 5.5 kg of compressed air is extracted from the system main network at a rate of 60 cubic meters per minute and slightly boosted to 7 kg. This meets the individual production needs of different plant areas, reduces the overall pressure of the company's compressed air network, and saves a large amount of electricity.

[0047] The master controller enhances the intelligent automatic adjustment means of the compressed air network, effectively reducing the pressure and flow fluctuations of the compressed air network in the whole plant, while ensuring the efficient operation of the centrifugal units and reducing the overall production and operation energy consumption. In this embodiment, the master controller controls all 8 large centrifugal and variable frequency screw air compressors. When it detects that the flow rate of compressed air at the input end is insufficient, the variable frequency screw air compressor is first turned on to increase the supply of 7680m 3 / h, then open the centrifugal compressor guide vanes to increase supply. If the supply is high, reduce the frequency converter screw compressor first, then reduce the centrifugal compressor guide vanes. The master controller controls the guide vanes and vent valves of the centrifugal compressors. When total supply exceeds total demand, it closes the guide vanes of several compressors, reducing supply and achieving balance. When total supply is less than total demand, it gradually opens the guide vanes of all compressors. If all are open and still insufficient, it activates the frequency converter screw compressor to eliminate the imbalance between total supply and total demand.

[0048] To sum up, the system for rapid adjustment of the compressed air network of a steel plant of the present invention introduces an external air compressor station to supply air to the steel plant on the basis of the original compressed air network of the steel plant, which saves a lot of cost of building an air compressor station by itself, and introduces the compressed air supply as surplus supply to the external air compressor station, effectively avoiding waste of resources; the present invention can detect abnormalities of the external air compressor station in the first time, generate an alarm signal, and automatically process and maintain the normal supply in the compressed air network, and dynamically adjust the supply of the internal air compressor station according to the detected pressure changes and flow changes in the pipeline, to ensure the normal operation of each gas-using equipment in the system, avoid the occurrence of safety accidents, save resources, and increase the efficiency of the steel plant.

[0049] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A method for regulating the compressed air network in a steel plant, characterized in that: The steps include: Obtain the operating current of the air compressor in the external air compression station and the pressure and flow values ​​in the external input branch pipe in real time; The operating status of the external air compressor station is judged according to the operating current, pressure value and flow value. If the operating status is abnormal, the internal regulating air compressor station is started, and the supply volume of the internal regulating air compressor station to the compressed air pipeline network is dynamically adjusted according to the change in the flow value.

2. The method for regulating the compressed air network in a steel plant according to claim 1, characterized in that: The method to judge the operating status of the external air compressor station is: When the pressure values ​​of at least two external input branches are detected to be lower than the pressure threshold, it indicates that the external air compressor station is operating abnormally and a pressure abnormality alarm signal is issued; When it is detected that the sum of the flow values ​​of all input branches decreases by more than the flow threshold, it indicates that the external air compressor station is operating abnormally and a flow abnormality alarm signal is issued; When it is detected that the operating current of the air compressor of the external air compressor station is lower than the current threshold, it indicates that the operating state of the external air compressor station is abnormal, and a current abnormality alarm signal is issued.

3. The method for regulating the compressed air network in a steel plant according to claim 2, characterized in that: When at least one of the pressure abnormality alarm signal, the flow abnormality alarm signal and the current abnormality alarm signal is received, the internal regulating air compression station is started.

4. The method for regulating the compressed air network in a steel plant according to claim 1, characterized in that: The internal regulating air compressor station includes a variable frequency screw air compressor and several centrifugal air compressors. The variable frequency screw air compressor is used for flow regulation when the input flow in the pipeline network fluctuates within a small range, and the centrifugal air compressor is used for flow regulation when the supply volume of the external air compressor station fluctuates within a large range.

5. The method for regulating the compressed air network in a steel plant according to claim 1, characterized in that: The method of dynamically adjusting the supply volume of the internal regulating air compressor station to the compressed air network according to the change in flow value is as follows: When the decrease in flow rate is detected to be greater than the flow fluctuation threshold and less than 7680m 3 / h, start the variable frequency screw air compressor of the internal regulating air compressor station to buffer the reduced supply of the external air compressor station; when the variable frequency screw air compressor reaches the maximum supply, when the flow value is detected to decrease by 15000 m 3 / h, a centrifugal air compressor is turned on to buffer the reduced supply from the external air compression station until the flow value in the input branch pipe no longer decreases.

6. A steel plant compressed air pipe network regulation system, characterized in that: The method according to any one of claims 1 to 5, comprising: Internal regulating air compressor station, connected to the internal compressed air network; The external air compression station is connected to the internal compressed air network through several external input branches, each of which is equipped with an inlet configuration valve, a monitoring unit and an outlet configuration valve; The main controller is respectively connected to the external air compression station, the internal regulating air compression station and the monitoring unit for communication, receives the operating current signal of the air compressor in the external air compression station in real time, receives the pressure value and flow value in the external input branch pipe measured by the monitoring unit in real time, and controls the supply amount of the internal regulating air compression station to the compressed air pipeline network according to the operating current, pressure value and flow value.

7. The compressed air pipe network regulating system for a steel plant according to claim 6, characterized in that: The monitoring unit includes a pressure sensor and a flow sensor. The pressure sensor collects the compressed air pressure value in the external input branch in real time and transmits it to the main controller. The flow sensor collects the compressed air flow value in the external input branch in real time and transmits it to the main controller. The sum of the flow rates of each external input branch is the output flow value of the external air compressor station.

8. The compressed air pipe network regulating system for a steel plant according to claim 6, characterized in that: The terminal gas-using plant area of ​​the internal compressed air network is provided with a pressure detection unit and a boosting unit. When it is detected that the pressure value of the terminal gas-using plant area is lower than the required pressure value, the boosting unit is started.

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