Stable oxygen supply system of smelting system

Abstract

The utility model discloses a stable oxygen supply system of a smelting system, and belongs to the technical field of smelting. The system comprises a first air separation device, a second air separation device, a first liquid oxygen gasification device and a second liquid oxygen gasification device, the first air separation device, the second air separation device and a first smelting system are communicated through a three-way pipeline, and the first liquid oxygen gasification device supplements and supplies oxygen to the first smelting system. And the second liquid oxygen gasification device supplies oxygen to the second smelting system and the third smelting system. According to the utility model, the liquid oxygen gasification device is introduced to bear the fluctuation of the production load rate, so that the air separation device can keep better production load stability, and meanwhile, oxygen supply balance is formed among different smelting systems, so that the waste of oxygen is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of oxygen supply for air separation devices and relates to a stable oxygen supply system for a smelting system. Background Art

[0002] The air separation unit is an industrial device used to separate the various gas components in the air and produce oxygen, nitrogen, argon and other gases of the air components. The oxygen and other gases produced can be provided to other production equipment or production systems as energy. The air separation unit is widely used in metallurgy, new coal chemical industry and other fields. However, the air separation unit has high requirements for production stability. If the load rate fluctuates greatly during the production process, it will affect the safety and service life of the air separation unit.

[0003] Liquid oxygen gasification units are more advanced than air separation units and are energy-saving products with higher efficiency. They are more adaptable to fluctuations in production load rates.

[0004] During the smelting production process, the smelting system needs to use oxygen. Currently, air separation units are usually used to supply oxygen to the smelting system. However, the oxygen consumption of the smelting system will fluctuate during the smelting production process. Therefore, if the air separation unit is used alone to supply oxygen to the smelting system, when the oxygen consumption of the smelting system fluctuates, the production load rate of the air separation unit will also fluctuate, thereby causing an adverse effect on the air separation unit. At the same time, since a margin needs to be left for the increase in oxygen consumption of the smelting system, the normal load rate of the air separation unit will be at a low state, which is not conducive to cost control.

[0005] For smelting production units, as the scale of production expands, the number of smelting systems will increase. Therefore, with the increase in smelting systems, the oxygen supply system needs to be optimized and improved accordingly. In the process of optimization and improvement, optimizing on the basis of the original oxygen supply system is an effective way to control costs, which is of great significance to the development of smelting production units. As a more advanced equipment, the liquid oxygen gasification unit becomes a better choice when optimizing the oxygen supply system of the air separation unit. At the same time, as the number of smelting systems increases, equipping a new smelting system with an independent oxygen supply system will lead to excessive costs, and it is impossible to form an oxygen supply balance between the smelting systems, which will further increase costs.

[0006] Therefore, the utility model provides a stable oxygen supply system for a smelting system, which changes the load rate of a liquid oxygen gasification device to adapt to fluctuations in oxygen consumption in the smelting system, reduces load rate fluctuations in an air separation device, and extends the service life of the air separation device. At the same time, an oxygen supply balance can be formed between different smelting systems to reduce oxygen waste and further reduce costs. Utility Model Content

[0007] In order to overcome the problems in the background technology, the utility model optimizes the oxygen supply system, introduces a liquid oxygen gasification device on the basis of the oxygen supply system of the air separation unit, and adjusts the production load rate of the liquid oxygen gasification device to meet the requirements of oxygen consumption fluctuations in the smelting system, thereby reducing the fluctuation of the production load rate of the air separation unit. At the same time, an oxygen supply balance is formed between different smelting systems, thereby reducing oxygen waste.

[0008] In order to achieve the above purpose, the utility model is implemented through the following technical solutions:

[0009] The oxygen supply system comprises a first air separation unit 1, a second air separation unit 2, a first liquid oxygen gasification unit 3, and a second liquid oxygen gasification unit 4. The first air separation unit 1, the second air separation unit 2, and a first smelting system 5 are connected through a three-way pipeline. The first liquid oxygen gasification unit 3 supplements oxygen supply to the first smelting system 5, and the second liquid oxygen gasification unit 4 supplements oxygen supply to the second smelting system 6 and the third smelting system 7, respectively. A first automatic control valve 8 is installed on the pipeline for the first liquid oxygen gasification unit 3 to supplement oxygen supply to the first smelting system 5, and a second automatic control valve 9 is installed on the pipeline for the second liquid oxygen gasification unit 4 to supplement oxygen supply to the second smelting system 6. A third automatic control valve 10 is installed on the pipeline for supplementing oxygen supply from the oxygen gasification unit 4 to the third smelting system 7, a fourth automatic control valve 11 is installed on the pipeline for supplying oxygen from the second air separation unit 2 to the second smelting system 6, a first flow pressure measuring point 12 is arranged on the combined pipeline for supplying oxygen from the first air separation unit 1, the second air separation unit 2 and the first liquid oxygen gasification unit 3 to the first smelting system 5, a second flow pressure measuring point 13 is arranged on the combined pipeline for supplying oxygen from the second air separation unit 2 and the second liquid oxygen gasification unit 4 to the second smelting system 6, and a third flow pressure measuring point 14 is arranged on the pipeline for supplying oxygen from the second liquid oxygen gasification unit 4 to the third smelting system 7.

[0010] The oxygen supply system also includes a DCS control system, and the measurement results of the first flow pressure measurement point 12, the second flow pressure measurement point 13, and the third flow pressure measurement point 14 are input into the DCS control system. Different output ends of the DCS control system are respectively communicated with the first automatic control valve 8, the second automatic control valve 9, the third automatic control valve 10, the fourth automatic control valve 11, the first air separation unit 1, the second air separation unit 2, the first liquid oxygen gasification unit 3, and the second liquid oxygen gasification unit 4.

[0011] Preferably, at the first flow pressure measurement point 12, the second flow pressure measurement point 13, and the third flow pressure measurement point 14, flow pressure composite sensors are installed to simultaneously measure the gas flow and pressure at the points, and the output end of the flow pressure composite sensor is communicatively connected with the input end of the DCS control system.

[0012] Preferably, the DCS control system presets flow and pressure thresholds.

[0013] Beneficial effects of the utility model:

[0014] 1. The utility model optimizes the oxygen supply system on the basis of continuous utilization of the original equipment. When supplying oxygen to multiple smelting systems, the oxygen supply of each smelting system is better balanced, thereby reducing oxygen waste and lowering oxygen supply costs.

[0015] 2. The utility model continuously utilizes the original oxygen supply equipment, and when the number of smelting systems increases, the effective load rate of the original oxygen supply equipment is improved, and the load rate of the original equipment can be maintained at more than 98%.

[0016] 3. The utility model introduces a liquid oxygen gasification device on the basis of the original equipment, and the liquid oxygen gasification device is used to bear the work of production load rate fluctuation, so that the original equipment can maintain a relatively stable load rate during the working process, reduce the loss of the original equipment, and extend the service life of the original equipment.

[0017] 4 The utility model uses a DCS control system and an oxygen supply system for automatic control, which can make the control more precise and the response more rapid.

[0018] 5. The utility model has a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the pipe network structure of the oxygen supply system of the utility model.

[0020] Figure 2 The figure is a comparison diagram of oxygen supply fluctuations before and after the optimization of the oxygen supply system, where Figure (a) is the oxygen supply fluctuation diagram of the original oxygen supply system, and Figure (b) is the oxygen supply fluctuation diagram of the optimized oxygen supply system.

[0021] In the figure, 1-the first air separation unit, 2-the second air separation unit, 3-the first liquid oxygen gasification unit, 4-the second liquid oxygen gasification unit, 5-the first smelting system, 6-the second smelting system, 7-the third smelting system, 8-the first automatic control valve, 9-the second automatic control valve, 10-the third automatic control valve, 11-the fourth automatic control valve, 12-the first flow pressure measurement point, 13-the second flow pressure measurement point, 14-the third flow pressure measurement point. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings to facilitate understanding by technicians.

[0023] like Figure 1As shown, the oxygen supply system includes a first air separation unit 1, a second air separation unit 2, a first liquid oxygen gasification unit 3, and a second liquid oxygen gasification unit 4. The first air separation unit 1, the second air separation unit 2, and the first smelting system 5 are connected through a three-way pipeline. The first liquid oxygen gasification unit 3 supplements oxygen supply to the first smelting system 5, and the second liquid oxygen gasification unit 4 supplements oxygen supply to the second smelting system 6 and the third smelting system 7 respectively. A first automatic control valve 8 is installed on the pipeline for the first liquid oxygen gasification unit 3 to supplement oxygen supply to the first smelting system 5, and a second automatic control valve 9 is installed on the pipeline for the second liquid oxygen gasification unit 4 to supplement oxygen supply to the second smelting system 6. A third automatic control valve 10 is installed on the pipeline for the liquid oxygen gasification device 4 to supplement the oxygen supply to the third smelting system 7, a fourth automatic control valve 11 is installed on the pipeline for the second air separation device 2 to supply oxygen to the second smelting system 6, a first flow pressure measurement point 12 is set on the combined pipeline for the first air separation device 1, the second air separation device 2, and the first liquid oxygen gasification device 3 to supply oxygen to the first smelting system 5, a second flow pressure measurement point 13 is set on the combined pipeline for the second air separation device 2 and the second liquid oxygen gasification device 4 to supply oxygen to the second smelting system 6, and a third flow pressure measurement point 14 is set on the pipeline for the second liquid oxygen gasification device 4 to supply oxygen to the third smelting system 7;

[0024] The oxygen supply system also includes a DCS control system, and the measurement results of the first flow pressure measurement point 12, the second flow pressure measurement point 13, and the third flow pressure measurement point 14 are input into the DCS control system. Different output ends of the DCS control system are respectively communicated with the first automatic control valve 8, the second automatic control valve 9, the third automatic control valve 10, the fourth automatic control valve 11, the first air separation unit 1, the second air separation unit 2, the first liquid oxygen gasification unit 3, and the second liquid oxygen gasification unit 4.

[0025] At the first flow pressure measurement point 12, the second flow pressure measurement point 13, and the third flow pressure measurement point 14, flow pressure composite sensors are installed to simultaneously measure the gas flow and pressure at the points, and the output end of the flow pressure composite sensor is communicatively connected with the input end of the DCS control system.

[0026] The DCS control system presets flow and pressure thresholds.

[0027] The oxygen supply of the oxygen supply system is determined by the oxygen consumption of the smelting system. That is, when the smelting system consumes a large amount of oxygen, the smelting system will absorb more oxygen, thereby increasing the oxygen flow in the oxygen supply pipeline. At the moment the oxygen flow increases, the pressure in the oxygen supply pipeline will decrease. When the smelting system consumes a small amount of oxygen, the smelting system will absorb less oxygen, and the oxygen flow in the oxygen supply pipeline will decrease. At this time, the pressure in the oxygen supply pipeline will rise. Therefore, by measuring the oxygen flow and pressure in the oxygen supply pipeline, the oxygen consumption of the smelting system can be known.

[0028] The first air separation unit 1 and the second air separation unit 2 are oxygen supply equipment in the original oxygen supply system. As the number of smelting systems increases, it is necessary to optimize the oxygen supply system based on the first air separation unit 1 and the second air separation unit 2.

[0029] After optimization, the first air separation unit 1 and the second air separation unit 2 can meet the oxygen demand of the first smelting system 5, the second smelting system 6, and the third smelting system 7 under higher load conditions, that is, in the normal production process of the three smelting systems, only the first air separation unit 1 and the second air separation unit 2 can meet the oxygen demand of the smelting system. During this process, the fourth automatic control valve 11 is in a normally open state. At the same time, the flow rate and pressure thresholds preset in the DCS control system are also the oxygen flow rate and pressure values ​​in the oxygen supply pipeline when the first air separation unit 1 and the second air separation unit 2 are running at high load during the normal production process of the smelting system.

[0030] When the oxygen consumption of the first smelting system 5, the second smelting system 6 and the third smelting system 7 increases during the production process, the flow rates measured at the first flow pressure measurement point 12, the second flow pressure measurement point 13 and the third flow pressure measurement point 14 will increase instantaneously, while the pressure will decrease instantaneously. After the DCS control system receives the measurement data of each flow pressure measurement point, due to the increase in oxygen flow and the decrease in pressure, the oxygen flow measurement data will be greater than the flow threshold preset in the DCS control system, and the pressure measurement data will be lower than the pressure threshold preset in the DCS control system. At this time, the DCS control system controls the first automatic control valve 8, the second automatic control valve 9 and the third automatic control valve 10 to open, the first liquid oxygen gasification device 3 supplements oxygen supply to the first smelting system 5, and the second liquid oxygen gasification device 4 supplements oxygen supply to the second smelting system 6 and the third smelting system 7 to meet the increase in oxygen consumption of the smelting system.

[0031] When the first smelting system 5, the second smelting system 6, and the third smelting system 7 all experience a decrease in oxygen consumption during the production process, the flow rates measured at the first flow pressure measurement point 12, the second flow pressure measurement point 13, and the third flow pressure measurement point 14 will decrease instantaneously, while the pressure will increase instantaneously. After the DCS control system receives the measurement data of each flow pressure measurement point, due to the decrease in oxygen flow and the increase in pressure, the oxygen flow measurement data will be less than the flow threshold preset in the DCS control system, and the pressure measurement data will be higher than the pressure threshold preset in the DCS control system. At this time, the first automatic control valve 8, the second automatic control valve 9, and the third automatic control valve 10 are all in a closed state, and the DCS control system controls the first air separation unit 1 and the second air separation unit 2 to vent and exhaust oxygen, so that part of the oxygen is discharged into the air to meet the reduced oxygen demand of the smelting system.

[0032] When the oxygen consumption of different smelting systems increases or decreases, for example, when the oxygen consumption of the first smelting system 5 increases, the oxygen consumption of the second smelting system 6 decreases, and the oxygen consumption of the third smelting system 7 remains unchanged, the oxygen flow measurement value of the first flow pressure measurement point 12 will instantly increase and exceed the preset threshold, and the pressure measurement value will instantly decrease and fall below the preset threshold, while the oxygen flow at the second flow pressure measurement point 13 will instantly decrease and fall below the preset threshold, and the pressure measurement value will instantly increase and rise above the threshold. At this time, the DCS control system controls the first automatic control valve 3 to open a smaller opening, so that the first liquid oxygen gasification device 3 provides less supplementary oxygen supply to the first smelting system 5, and at the same time controls the fourth automatic control valve 11 to adjust the opening to a smaller degree, reducing the oxygen supply of the oxygen supply system to the second smelting system 6, so that the second smelting system 6 The excess oxygen supply can be used to supply oxygen to the first smelting system 5 without venting and exhausting, thereby reducing oxygen waste. If the oxygen consumption reduced by the second smelting system 6 is greater than the oxygen consumption increased by the first smelting system 1, the oxygen supply is still at a high level at this time, so that the pressure measurement value of the first flow pressure measurement point 12 will rise to be greater than the threshold value. After receiving the pressure signal of the first flow pressure measurement point 12, the DCS controls the first automatic control valve 8 to reduce the opening or directly closes the first automatic control valve 8 to reduce the oxygen supply to the first smelting system 5. If the pressure measurement value of the first flow pressure measurement point 12 is still higher than the preset threshold value after the first automatic control valve 8 is closed, the DCS control system needs to control the first air separation unit 1 and the second air separation unit 2 to vent and exhaust. Similarly, when the oxygen consumption of the second smelting system 6 increases and the oxygen consumption of the first smelting system 5 or the third smelting system 7 decreases, the DCS control system controls the second automatic control valve 9 to open to supplement the oxygen supply to the second smelting system 6. At this time, the fourth automatic control valve 11 remains open to supply excess oxygen from other smelting systems to the second smelting system 6. The same control method is also used for the third smelting system 7. When the oxygen consumption of the third smelting system 7 increases and the oxygen consumption of the first smelting system 5 or the second smelting system 6 decreases, the DCS control system controls the third automatic control valve 10 to open, and the second liquid oxygen gasification device 4 supplements the oxygen supply to the third smelting system 7. At the same time, the opening of the fourth automatic control valve 11 is reduced to allow more oxygen to enter the third smelting system 7.

[0033] When the oxygen consumption of the smelting system increases first and then decreases, the required oxygen flow rate after the decrease may not be lower than the preset oxygen flow rate threshold. For example, when the oxygen consumption of other smelting systems remains unchanged, the preset oxygen flow rate threshold is 16000Nm 3 / h, and the oxygen consumption of the first smelting system 5 is first increased to 16500Nm 3 / h, at this time, the oxygen flow measurement value is greater than the preset threshold, and the pressure measurement value will instantly drop to less than the preset threshold. After receiving the signal, the DCS controls the first automatic control valve 8 to open, and supplements the oxygen supply to the first smelting system 5. When the oxygen supply is stable, the pressure measurement value will return to the preset threshold, and the oxygen flow rate will remain unchanged. When the oxygen consumption of the first smelting system 5 increases from 16500Nm 3 / h down to 16300Nm 3 / h, at this time the oxygen flow rate is not lower than the preset threshold value, and the DCS control system cannot be controlled according to the oxygen flow rate signal, but the pressure measurement value will become larger and higher than the preset threshold value. After receiving the pressure measurement value signal, the DCS control system controls the first automatic control valve 8 to reduce the opening or directly close it, so that the pressure measurement value is restored to the preset threshold value to meet the oxygen demand of the first smelting system 5.

[0034] Since the oxygen consumption of different smelting systems may increase or decrease, for example, the oxygen consumption of the first smelting system 5 increases, and the oxygen consumption of the second smelting system 6 or the third smelting system 7 decreases, the total oxygen supply of the oxygen supply system can be kept relatively stable, and only the oxygen consumption of a single smelting system fluctuates. Therefore, the oxygen supply fluctuation of the oxygen supply system can be controlled within a smaller range (such as Figure 2 shown).

[0035] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the utility model.

Claims

1. A stable oxygen supply system for a smelting system, characterized in that: The oxygen supply system comprises a first air separation unit (1), a second air separation unit (2), a first liquid oxygen gasification unit (3), and a second liquid oxygen gasification unit (4). The first air separation unit (1), the second air separation unit (2), and a first smelting system (5) are connected via a three-way pipeline. The first liquid oxygen gasification unit (3) supplies oxygen to the first smelting system (5). The second liquid oxygen gasification unit (4) supplies oxygen to the second smelting system (6) and the third smelting system (7). A first automatic control valve (8) is installed on a pipeline for the first liquid oxygen gasification unit (3) to supply oxygen to the first smelting system (5). A second automatic control valve (9) is installed on a pipeline for the second liquid oxygen gasification unit (4) to supply oxygen to the second smelting system (6). A third automatic control valve (10) is installed on the pipeline for supplementing oxygen supply from the oxygen gasification device (4) to the third smelting system (7); a fourth automatic control valve (11) is installed on the pipeline for supplying oxygen from the second air separation device (2) to the second smelting system (6); a first flow pressure measurement point (12) is arranged on the combined pipeline for supplying oxygen from the first air separation device (1), the second air separation device (2) and the first liquid oxygen gasification device (3) to the first smelting system (5); a second flow pressure measurement point (13) is arranged on the combined pipeline for supplying oxygen from the second air separation device (2) and the second liquid oxygen gasification device (4) to the second smelting system (6); and a third flow pressure measurement point (14) is arranged on the pipeline for supplying oxygen from the second liquid oxygen gasification device (4) to the third smelting system (7); The oxygen supply system further comprises a DCS control system, wherein the measurement results of the first flow pressure measurement point (12), the second flow pressure measurement point (13) and the third flow pressure measurement point (14) are input into the DCS control system, and different output ends of the DCS control system are respectively connected to the first automatic control valve (8), the second automatic control valve (9), the third automatic control valve (10), the fourth automatic control valve (11), the first air separation device (1), the second air separation device (2), the first liquid oxygen gasification device (3) and the second liquid oxygen gasification device (4) for communication.

2. The stable oxygen supply system for a smelting system according to claim 1, characterized in that: At the first flow pressure measurement point (12), the second flow pressure measurement point (13), and the third flow pressure measurement point (14), flow pressure composite sensors are installed to simultaneously measure the gas flow and pressure at the points, and the output end of the flow pressure composite sensor is communicatively connected with the input end of the DCS control system.

3. The stable oxygen supply system for a smelting system according to claim 1, characterized in that: The DCS control system presets flow and pressure thresholds.

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