Valley storage and peak supply gas supply system and control method

Abstract

The invention belongs to the technical field of gas supply in the smelting industry, and particularly discloses a valley storage and peak supply gas supply system which comprises a gas production unit and a DCS control system, a gas supply pipe is communicated with the gas production unit, a gas supply unit and an adjusting pipe are communicated with the gas supply pipe, an automatic control valve is arranged at the communication position of the adjusting pipe and the gas supply pipe, and two adjusting branch pipes are communicated with the adjusting pipe. Each adjusting branch pipe is respectively communicated with a spherical tank group A and a spherical tank group B, pressure transmitters are arranged on the gas using unit, the gas generating unit and the adjusting pipes, and the self-control valves and the pressure transmitters are electrically connected with a DCS (Distributed Control System); the gas consumption of the gas using unit and the gas production of the gas producing unit are balanced by supplying gas at the gas using peak and storing gas at the gas using low peak through the spherical tank A group and the spherical tank B, and unbalance between the gas using unit and the gas producing unit is reduced, so that great fluctuation and waste of gas are reduced; the problems that in the metallurgical smelting process, gas consumption is unbalanced or periodic production and use is unbalanced, and consequently gas pressure fluctuates and is diffused greatly are solved.

Description

Technical Field

[0001] This invention relates to the field of gas supply technology in the smelting industry, specifically to a gas supply system and control method that combines valley storage and peak delivery. Background Technology

[0002] In metallurgical smelting processes, the consumption of industrial gases such as oxygen, nitrogen, and argon is not continuous and balanced, but rather closely linked to specific processes such as blowing, refining, stirring, and cooling, exhibiting dramatic pulse-like fluctuations. For example, during converter oxygen blowing for decarburization, oxygen demand reaches its peak instantaneously; while in electric arc furnace smelting or ladle refining, argon consumption increases sharply when used for stirring, but is almost zero during intermittent periods. Periodic imbalances in production and consumption are caused by mismatches between production shifts and the operation of the gas supply system. For example, during daytime shifts, due to factors such as routine equipment maintenance and concentrated personnel operation, the actual gas consumption may be lower than the average gas supply provided by the continuous and stable operation of the air separation unit. This results in excess gas being continuously injected into the storage tank, manifested as a continuous rise in tank pressure. This not only may approach the safety limit and cause waste due to venting, but also means ineffective storage of the compression function. Conversely, during the night shift, production is in full swing while the gas supply capacity remains constant. The gas demand exceeds the average gas supply, and the gas must be replenished by the gas reserves in the storage tanks. This causes a sharp drop in the pressure of the storage tanks, making it difficult to match the gas supply system's capacity with the instantaneous demand of the smelting process in real time, resulting in a periodic supply-demand imbalance.

[0003] The direct consequences are: during peak gas consumption periods, it affects smelting efficiency and product quality, and may even lead to production safety risks; during off-peak periods, it causes frequent start-ups and shutdowns or large releases of the gas supply system, resulting in low energy efficiency and increased equipment wear and tear. Summary of the Invention

[0004] The purpose of this invention is to provide a gas supply system and control method for peak-valley storage and peak-sending, in order to solve the problem of large fluctuations and venting of gas pressure caused by imbalances in gas consumption or periodic production and consumption in metallurgical smelting processes.

[0005] To achieve the above objectives, the basic solution provided by this invention is as follows: a gas supply system for peak-valley storage and delivery, comprising a gas generating unit and a DCS control system. The gas generating unit is connected to a gas delivery pipe, which is connected to a gas user unit and a regulating pipe. An automatic control valve is provided at the connection between the regulating pipe and the gas delivery pipe. Two regulating branch pipes are connected to the regulating pipe, and each regulating branch pipe is connected to a group of spherical tanks A and B, respectively. Pressure transmitters are provided on the gas user unit, the gas generating unit, and the regulating pipe. The automatic control valve and the pressure transmitters are electrically connected to the DCS control system.

[0006] The working principle and beneficial effects of this invention are as follows: When either spherical tank group A or spherical tank group B requires maintenance, the two tank groups can serve as backup tanks for each other; during off-peak gas consumption periods, the gas production unit generates more gas than the gas consumption unit consumes. The DCS control system controls the opening of the automatic control valve based on the pressure of the gas consumption unit, the gas production unit, and the regulating pipe, sending the excess gas into spherical tank groups A and B for storage, reducing frequent start-ups or venting of the gas production unit, thereby improving energy utilization and reducing equipment wear; during peak gas consumption periods, the gas production unit generates more gas than the gas consumption unit consumes. The gas consumption of the gas-consuming unit exceeds the gas production of the gas-generating unit. The DCS control system controls the opening of the automatic control valves based on the pressure of the gas-consuming unit, the gas-generating unit, and the regulating pipe. Spherical tanks A and B replenish the gas-consuming unit, reducing the impact on product quality and smelting efficiency. By supplying gas during peak gas consumption periods and storing gas during off-peak periods through spherical tanks A and B, the gas consumption of the gas-consuming unit and the gas production of the gas-generating unit are balanced, reducing the imbalance between the two units and thus minimizing large fluctuations and waste in gas consumption.

[0007] Option 2, which is the preferred option of the basic option, is equipped with a manual valve 1 and a manual valve 2 on each regulating branch pipe, and the automatic control valve is a three-way pneumatic regulating valve; when spherical tank group A or spherical tank group B needs maintenance, the corresponding manual valve is closed to increase the safety of maintenance personnel.

[0008] Option 3, which is the basic solution provided by this invention: a gas supply control method for peak-valley storage and delivery, comprising the following steps: S1. Set the pressure threshold of the regulating pipe on the human-machine interface of the DCS control system. The pressure transmitter detects the pressure on the gas-consuming unit, the gas-producing unit and the regulating pipe, and transmits the real-time pressure to the DCS control system. After receiving the pressure transmitted by the pressure transmitter, the S2.DCS control system compares the pressure of the gas-consuming unit and the gas-producing unit. When the pressure of the gas-consuming unit is greater than the pressure of the gas-producing unit, spherical tank A and spherical tank B supply gas to the outside; when the pressure of the gas-consuming unit is less than the pressure of the gas-producing unit, spherical tank A and spherical tank B store gas inside. S3. When spherical tank A and spherical tank B are storing gas, the DCS control system controls whether the automatic control valve opens based on the pressure of the regulating pipe. When spherical tank group A and spherical tank group B are replenishing gas, the DCS control system controls whether the automatic control valve opens based on the pressure of the regulating pipe. S4. When the automatic control valve opens, the DCS control system controls the opening degree of the automatic control valve according to the actual pressure of the regulating pipe until the pressure of the gas-consuming unit is equal to the pressure of the gas-producing unit.

[0009] Option 4, which is the preferred option of Option 3, involves adjusting the pressure threshold of the regulating pipe in step S1 to 1.5-2.5 MPa.

[0010] Option 5, which is the preferred option of Option 3, involves step S2 where the pressure of the gas-consuming unit equals the pressure of the gas-producing unit, and the DCS control system controls the automatic control valve to close.

[0011] Option 6, which is the preferred option of Option 3, in step S3, when spherical tank A and spherical tank B store gas, and 1.5MPa < pressure of regulating pipe ≤ 2.5MPa, the DCS control system controls the automatic control valve to open; when 2.5MPa < pressure of regulating pipe, the DCS control system controls the automatic control valve to close. When spherical tanks A and B supply gas, and the pressure of the regulating pipe is less than 1.5 MPa and less than or equal to 2.5 MPa, the DCS control system opens the automatic control valve. When the pressure of the regulating pipe is less than 1.5 MPa, the DCS control system closes the automatic control valve.

[0012] Option 7, which is a preferred option of Option 3, involves the following steps in step S4: When spherical tanks A and B are storing gas, and the pressure of the regulating pipe is less than 2.3 MPa and less than 2.5 MPa, the DCS control system controls the opening of the automatic control valve to be 50-100%. When the pressure of the regulating pipe is less than 1.8 MPa and less than 2.3 MPa, the DCS control system controls the opening of the automatic control valve to be 30-50%. When the pressure of the regulating pipe is less than 1.5 MPa and less than 1.8 MPa, the DCS control system controls the opening of the automatic control valve to be 0-30%, until the pressure of the gas-consuming unit equals the pressure of the gas-producing unit. When spherical tanks A and B supply gas, and the pressure of the regulating pipe is between 1.8 MPa and 2.5 MPa, the DCS control system controls the opening of the automatic control valve to be 30-70%. When the pressure of the regulating pipe is between 1.5 MPa and 1.8 MPa, the DCS control system controls the opening of the automatic control valve to be 0-30%, until the pressure of the gas-consuming unit equals the pressure of the gas-producing unit. During the gas storage stage, controlling the gas intake speed by controlling the valve opening can reduce the gas temperature rise, thereby reducing the fatigue stress on the tank structure caused by drastic temperature changes. During the gas delivery stage, it can quickly meet the peak demand of the gas-consuming unit. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a peak-storage gas supply system according to the present invention. Detailed Implementation

[0014] The present invention will be further described in detail below through specific embodiments: The reference numerals in the accompanying drawings of the instruction manual include: 1. Gas-consuming unit, 2. Gas delivery pipe, 3. Gas-producing unit, 4. Regulating pipe, 5. Regulating branch pipe, 6. Spherical tank group A, 7. Spherical tank group B, 8. Automatic control valve, 9. Manual valve one, 10. Manual valve two, 11. Pressure transmitter.

[0015] Example 1 like Figure 1 As shown: A peak-storage gas supply system includes a gas generator unit 3 and a DCS control system. The gas generator unit 3 is connected to a gas delivery pipe 2, which is connected to a gas user unit 1 and a regulating pipe 4. A self-control valve 8 is installed at the connection between the regulating pipe 4 and the gas delivery pipe 2. The self-control valve 8 is a three-way pneumatic regulating valve, model 48000 series. Two regulating branch pipes 5 are connected to the regulating pipe 4. Each regulating branch pipe 5 is connected to a spherical tank group A 6 and a spherical tank group B 7, respectively. Each regulating branch pipe 5 is equipped with a manual valve 1 9 and a manual valve 2 10, respectively. Pressure transmitters 11, model EJA510E, are installed on the gas user unit 1, the gas generator unit 3, and the regulating pipe 4. The self-control valve 8 and the pressure transmitters 11 are electrically connected to the DCS control system.

[0016] The implementation method of this embodiment is as follows: when spherical tank group A6 or spherical tank group B7 needs maintenance, the corresponding manual valve is closed, and the two spherical tank groups can serve as reserve tanks for each other; During off-peak gas consumption periods, the amount of gas produced by gas generating unit 3 is greater than the amount of gas consumed by gas consuming unit 1. The DCS control system controls the opening of the automatic control valve 8 based on the pressure of gas consuming unit 1, gas generating unit 3 and regulating pipe 4, and sends the excess gas into spherical tank group A 6 and spherical tank group B 7 for storage, thereby reducing the frequent start-up and shutdown or venting of gas generating unit 3, thus improving energy utilization and reducing equipment wear. During peak gas consumption periods, the amount of gas used by gas-consuming unit 1 is greater than the amount of gas produced by gas-producing unit 3. The DCS control system controls the opening of the automatic control valve 8 based on the pressure of gas-consuming unit 1, gas-producing unit 3, and regulating pipe 4. Spherical tank group A 6 and spherical tank group B 7 replenish gas to gas-consuming unit 1 to reduce the impact on product quality and smelting efficiency.

[0017] Example 2 A gas supply control method for peak-storage and valley-to-peak gas delivery includes the following steps: S1. Set the pressure threshold of regulating pipe 4 to 1.5-2.5MPa on the human-machine interface of DCS control system. Pressure transmitter 11 detects the pressure on gas-consuming unit 1, gas-producing unit 3 and regulating pipe 4 and transmits the real-time pressure to DCS control system. After receiving the pressure transmitted by the pressure transmitter 11, the S2.DCS control system compares the pressure of the gas-consuming unit 1 and the gas-producing unit 3. When the pressure of the gas-consuming unit 1 is greater than the pressure of the gas-producing unit 3, the spherical tank A group 6 and the spherical tank B group 7 supply gas to the outside. When the pressure of gas-consuming unit 1 is less than the pressure of gas-producing unit 3, spherical tank A group 6 and spherical tank B group 7 store gas inside. When the pressure of gas-consuming unit 1 is equal to the pressure of gas-producing unit 3, the DCS control system controls the automatic control valve 8 to close. S3. When spherical tank A group 6 and spherical tank B group 7 store gas, and 1.5MPa < pressure of regulating pipe 4 ≤ 2.5MPa, the DCS control system controls the automatic control valve 8 to open; when 2.5MPa < pressure of regulating pipe 4, the DCS control system controls the automatic control valve 8 to close. When spherical tank A group 6 and spherical tank B group 7 supply gas externally, and the pressure of regulating pipe 4 is less than 1.5MPa and less than 2.5MPa, the DCS control system controls the automatic control valve 8 to open. When the pressure of regulating pipe 4 is less than 1.5MPa, the DCS control system controls the automatic control valve 8 to close. S4. When the automatic control valve 8 is opened, the DCS control system controls the opening degree of the automatic control valve 8 according to the actual pressure of the regulating pipe 4. When the spherical tank A group 6 and spherical tank B group 7 store gas, and 2.3MPa < pressure of regulating pipe 4 ≤ 2.5MPa, the DCS control system controls the opening degree of the automatic control valve 8 to be 50-100%. When 1.8MPa < pressure of regulating pipe 4 ≤ 2.3MPa, the DCS control system controls the opening degree of the automatic control valve 8 to be 30-50%. When 1.5MPa < pressure of regulating pipe 4 ≤ 1.8MPa, the DCS control system controls the opening degree of the automatic control valve 8 to be 0-30%, until the pressure of the gas-consuming unit 1 is equal to the pressure of the gas-producing unit 3. When spherical tanks A group 6 and B group 7 supply gas, and the pressure of regulating pipe 4 is less than 2.5 MPa and less than 1.8 MPa, the DCS control system controls the opening of the automatic control valve 8 to be 30-70%. When the pressure of regulating pipe 4 is less than 1.8 MPa and less than 1.5 MPa, the DCS control system controls the opening of the automatic control valve 8 to be 0-30%, until the pressure of gas-consuming unit 1 equals the pressure of gas-producing unit 3.

[0018] The implementation method of this embodiment is as follows: When the gas-consuming unit 1 needs to be repaired, the pressure of the gas-consuming unit 1 is less than the pressure of the gas-producing unit 3. The spherical tank group A 6 and the spherical tank group B 7 are in the internal gas storage state. When the pressure of the regulating pipe 4 is 1.7MPa, the DCS control system controls the opening degree of the self-control valve 8 to 20% until the pressure of the gas-consuming unit 1 is equal to the pressure of the gas-producing unit 3. When gas-consuming unit 1 is in peak gas consumption, the pressure of gas-consuming unit 1 is greater than the pressure of gas-producing unit 3. Spherical tanks A group 6 and B group 7 are in the state of supplying gas. When the pressure of regulating pipe 4 is 2.1MPa, the DCS control system controls the opening of the automatic control valve 8 to 60% until the pressure of gas-consuming unit 1 equals the pressure of gas-producing unit 3.

[0019] When the total gas consumption of gas-using unit 1 is 50,000 Nm 3 / h, the total gas production of gas-producing unit 3 is 40,000-55,000 Nm³. 3 / h, the capacity of both spherical tank A group 6 and spherical tank B group 7 is 30000Nm 3The comparison of the time for regulating the pressure of the four-network system and the amount of gas released before and after the improvement is shown in Table 1 below: Table 1 Comparison of pressure adjustment time and gas emission before and after improvement The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A gas supply system for peak-shaving and valley-storage gas delivery, characterized in that, The system includes a gas generating unit (3) and a DCS control system. The gas generating unit (3) is connected to a gas supply pipe (2). The gas supply pipe (2) is connected to a gas user unit (1) and a regulating pipe (4). A self-control valve (8) is provided at the connection between the regulating pipe (4) and the gas supply pipe (2). Two regulating branches (5) are connected to the regulating pipe (4). Each regulating branch (5) is connected to a spherical tank group A (6) and a spherical tank group B (7). Pressure transmitters (11) are provided on the gas user unit (1), the gas generating unit (3), and the regulating pipe (4). The self-control valve (8) and the pressure transmitters (11) are electrically connected to the DCS control system.

2. The gas supply system for peak-storage and peak-delivery according to claim 1, characterized in that, Each of the regulating branch pipes (5) is provided with a first hand valve (9) and a second hand valve (10), and the self-control valve (8) is a three-way pneumatic regulating valve.

3. A gas supply control method for peak-valley storage and delivery, characterized in that, Includes the following steps: S1. Set the pressure threshold of the regulating pipe (4) on the human-machine interface of the DCS control system. The pressure transmitter (11) detects the pressure on the gas-consuming unit (1), the gas-producing unit (3) and the regulating pipe (4) and transmits the real-time pressure to the DCS control system. After receiving the pressure transmitted by the pressure transmitter (11), the S2.DCS control system compares the pressure of the gas-consuming unit (1) and the gas-producing unit (3). When the pressure of the gas-consuming unit (1) is greater than the pressure of the gas-producing unit (3), the spherical tank group A (6) and spherical tank group B (7) replenish gas externally; when the pressure of the gas-consuming unit (1) is less than the pressure of the gas-producing unit (3), the spherical tank group A (6) and spherical tank group B (7) store gas internally. S3. When spherical tank A group (6) and spherical tank B group (7) store gas inside, the DCS control system controls whether the self-control valve (8) opens according to the pressure of the regulating pipe (4); When spherical tank group A (6) and spherical tank group B (7) replenish gas, the DCS control system controls whether the self-control valve (8) opens according to the pressure of the regulating pipe (4); S4. When the self-control valve (8) is opened, the DCS control system controls the opening degree of the self-control valve (8) according to the actual pressure of the regulating pipe (4) until the pressure of the gas-using unit (1) is equal to the pressure of the gas-producing unit (3).

4. The gas supply control method for peak-storage and peak-delivery gas supply according to claim 3, characterized in that, In step S1, the pressure threshold of the regulating pipe (4) is 1.5-2.5 MPa.

5. The gas supply control method for peak-storage and peak-delivery gas supply according to claim 3, characterized in that, In step S2, When the pressure of the gas-consuming unit (1) is equal to the pressure of the gas-producing unit (3), the DCS control system controls the automatic control valve (8) to close.

6. The gas supply control method for peak-storage and peak-delivery gas supply according to claim 3, characterized in that, In step S3, when the spherical tank group A (6) and spherical tank group B (7) store gas inside, and the pressure of the regulating pipe (4) is less than 1.5MPa and less than 2.5MPa, the DCS control system controls the self-control valve (8) to open; when the pressure of the regulating pipe (4) is less than 2.5MPa, the DCS control system controls the self-control valve (8) to close. When the spherical tanks A group (6) and B group (7) supply gas to the outside, and the pressure of the regulating pipe (4) is less than 1.5MPa and less than 2.5MPa, the DCS control system controls the automatic control valve (8) to open. When the pressure of the regulating pipe (4) is less than 1.5MPa, the DCS control system controls the automatic control valve (8) to close.

7. The gas supply control method for peak-storage and peak-delivery gas supply according to claim 3, characterized in that, In step S4, when the spherical tank group A (6) and spherical tank group B (7) store gas, and the pressure of the regulating pipe (4) is less than 2.3MPa and less than 2.5MPa, the DCS control system controls the opening of the self-control valve (8) to be 50-100%. When the pressure of the regulating pipe (4) is less than 1.8MPa and less than 2.3MPa, the DCS control system controls the opening of the self-control valve (8) to be 30-50%. When the pressure of the regulating pipe (4) is less than 1.5MPa and less than 1.8MPa, the DCS control system controls the opening of the self-control valve (8) to be 0-30%, until the pressure of the gas-consuming unit (1) is equal to the pressure of the gas-producing unit (3). When the gas supply from spherical tank group A (6) and spherical tank group B (7) is 1.8MPa < the pressure of regulating pipe (4) ≤ 2.5MPa, the DCS control system controls the opening of the self-control valve (8) to be 30-70%. When the pressure of regulating pipe (4) is 1.5MPa < the pressure of regulating pipe (4) ≤ 1.8MPa, the DCS control system controls the opening of the self-control valve (8) to be 0-30%, until the pressure of the gas-consuming unit (1) is equal to the pressure of the gas-producing unit (3).

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