Control system and method for online switching of double-converter gas holder

Abstract

The invention discloses a control system and method for online switching of double converter gas cabinets. Comprising a first converter gas holder and a second converter gas holder which are connected in parallel between a front-holder gas recovery header pipe and a rear-holder gas recovery header pipe; the first converter gas holder inlet pipeline is at least provided with an inlet electric butterfly valve, and the first converter gas holder outlet pipeline is at least provided with an outlet electric butterfly valve; at least a piston position detection device is arranged in the first converter gas holder; the second converter gas holder inlet pipeline is at least provided with an inlet electric butterfly valve, and the second converter gas holder outlet pipeline is at least provided with an outlet electric butterfly valve; at least a piston position detection device is arranged in the second converter gas holder; and the control device is used for controlling the opening or closing of the inlet electric butterfly valve according to signals output by the piston position detection device of the first converter gas holder and the piston position detection device of the second converter gas holder, so that the first converter gas holder or the second converter gas holder is in an online state.

Description

Technical Field

[0001] This invention relates to a control system and method for online switching of gas holders in dual converters. Background Technology

[0002] Converter gas holders primarily address the conflict between the intermittent production of converter steelmaking and the continuous use of converter gas by users. To ensure full recovery and utilization of converter gas during maintenance and prevent energy waste, many steel companies install two converter gas holders in parallel. There are two operating modes for parallel converter gas holders: one is joint operation, requiring both gas holders to be online simultaneously; the other is separate operation, with the gas holders serving as the main and auxiliary holders, requiring switching between them.

[0003] Chinese patent CN202210136345.4 proposes an automatic control method for a converter gas recovery dual gas holder system. This patent addresses the problem of frequent operator intervention caused by imbalances in the recovered gas volume between the two gas holders and imbalances in the gas holder capacity and the operation of the gas compressor. It proposes an automatic control method for simultaneous recovery of converter gas from two gas holders. The main method, under the premise that all interlocking devices of the gas holders, gas electrostatic precipitator, and gas compressor are functioning normally and the equipment is inherently safe, adjusts the opening of the regulating valve on the gas inlet pipe of the converter gas holders based on previous equipment operating parameters to ensure a balance in the recovered gas volume between the two gas holders. Simultaneously, it adjusts the compressor speed to keep the gas holders as close to the middle position as possible, avoiding situations where the gas holder capacity is too high and recovery is refused, or the gas compressor stops due to too low a capacity. This patent primarily focuses on the automatic control method for systems where two gas holders recover gas simultaneously.

[0004] Chinese patent CN202022964395.0 proposes a dual-cabinet parallel switching system for converter gas recovery. This patent addresses the modification of two independent converter gas recovery, purification, and dust removal systems. By adding valves and connecting pipes before the gas holders, it achieves a switch from simultaneously recovering converter gas from two gas holders to recovering converter gas from only one gas holder. This allows one gas holder to be removed from the system at any time, ensuring a continuous gas supply and avoiding gas release during gas holder maintenance. This patent primarily focuses on the automatic control method for switching from simultaneous recovery from two gas holders to recovery from only one converter gas holder.

[0005] The above patents mainly address the control method of a system in which two gas holders operate together. However, existing patents do not report on how to achieve online switching when the two gas holders operate as a main holder and an auxiliary holder, and when the main holder and the auxiliary holder switch to each other. Summary of the Invention

[0006] To address the above problems, this invention provides a control system and method for online switching of dual converter gas holders.

[0007] To achieve the above objectives, the present invention provides a control system for online switching of dual converter gas holders, comprising a first converter gas holder, a second converter gas holder, a gas recovery main pipe before the gas holder, a gas recovery main pipe after the gas holder, and a control device. The first and second converter gas holders are connected in parallel between the gas recovery main pipe before the gas holder and the gas recovery main pipe after the gas holder. The gas recovery main pipe after the gas holder is connected to the converter gas electrostatic precipitator and then to the converter gas pressurization station. After purification and pressurization, the gas is delivered to the user. At least one electric butterfly valve is installed on the inlet pipe of the first converter gas holder, and at least one electric butterfly valve is installed on the outlet pipe of the first converter gas holder; at least one piston position detection device is installed inside the first converter gas holder. At least one electric butterfly valve shall be installed on the inlet pipe of the second converter gas holder and at least one electric butterfly valve shall be installed on the outlet pipe of the second converter gas holder; at least one piston position detection device shall be installed inside the second converter gas holder. The control device controls the opening or closing of the inlet electric butterfly valve based on the signals output by the piston position detection device of the first converter gas holder and the piston position detection device of the second converter gas holder, so as to keep the first converter gas holder or the second converter gas holder online.

[0008] Furthermore, the inlet pipe of the first converter gas holder is also equipped with an inlet electric blind valve and an inlet pneumatic quick-cut valve, and the outlet pipe of the first converter gas holder is equipped with an outlet pneumatic quick-cut valve and an outlet electric blind valve.

[0009] Furthermore, the inlet pipe of the second converter gas holder is also equipped with an inlet electric blind valve and an inlet pneumatic quick-cut valve, and the outlet pipe of the second converter gas holder is equipped with an outlet pneumatic quick-cut valve and an outlet electric blind valve.

[0010] Furthermore, the first converter gas holder is also equipped with a piston speed detection device, a piston tilt detection device, a piston drift detection device, and a fixed CO alarm detection device on the upper part of the piston.

[0011] Furthermore, the second converter gas holder is also equipped with a piston speed detection device, a piston tilt detection device, a piston drift detection device, and a fixed CO alarm detection device on the upper part of the piston.

[0012] Furthermore, an oxygen content analyzer, a gas temperature detection device, and a gas pressure detection device are installed on the gas recovery main pipe in front of the cabinet.

[0013] Furthermore, an oxygen content analyzer is installed on the main gas pipe behind the cabinet.

[0014] Furthermore, a converter gas electrostatic precipitator and a converter gas pressurization station are sequentially installed at the outlet of the main gas recovery pipe after the gas is installed behind the cabinet. The converter gas is then purified and pressurized before being delivered to the user.

[0015] To achieve the above objectives, the present invention provides a control method for online switching of dual converter gas holders. The method is based on the aforementioned system and includes the following steps: Real-time monitoring of whether the current capacity of the online converter gas holder can meet the uninterrupted gas supply from the compressor within a smelting cycle, and whether the current capacity of the online converter gas holder is still not less than the low-level capacity interlock value under the condition that gas is only discharged and not introduced after a smelting cycle; If so, the inlet electric butterfly valve of the currently online converter gas holder should be closed first, and then the inlet electric butterfly valve of the currently offline converter gas holder should be opened to allow gas to enter the currently offline converter gas holder and recover gas for one smelting cycle. After a certain amount of gas has been recovered, the outlet electric butterfly valve of the currently offline converter gas holder should be opened and the outlet electric butterfly valve of the currently online converter gas holder should be closed. At this point, the online switching between the currently offline converter gas holder and the currently online converter gas holder is complete.

[0016] This invention addresses a dual converter gas holder system, where one is in use and the other is on standby, operating in parallel between the converter and the purification and pressurization equipment. It proposes a control logic to ensure safe online switching between the two holders and reduce converter gas venting when one converter gas holder is taken out of the system and the other is put into operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the dual converter gas holder of the present invention.

[0018] Figure 2 This is a flowchart of Case 1 of the present invention.

[0019] Figure 3 This is a flowchart of scenario 2 of the present invention.

[0020] Drawing number explanations: 1—First converter gas holder, 101—Inlet pipe of first converter gas holder, 102—Inlet electric butterfly valve, 103—Inlet electric blind valve, 104—Inlet pneumatic quick-cut valve, 105—Outlet pipe of first converter gas holder, 106—Outlet pneumatic quick-cut valve, 107—Outlet electric blind valve, 108—Outlet electric butterfly valve; 2—Second converter gas holder, 201—Inlet pipe of second converter gas holder, 202—Inlet electric butterfly valve, 203—Inlet electric blind valve, 204—Inlet pneumatic quick-cut valve, 205—Outlet pipe of second converter gas holder, 206—Outlet pneumatic quick-cut valve, 207—Outlet electric blind valve, 208—Outlet electric butterfly valve; 3—Gas recovery main pipe before the holder, 301—Oxygen content analyzer; 4—Gas recovery main pipe after the holder, 401—Oxygen content analyzer; 5—Electrostatic precipitator, 6—Pressure press. Detailed Implementation

[0021] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0022] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Figure 1The control system for online switching of dual converter gas holders of the present invention includes a first converter gas holder, a second converter gas holder, a gas recovery main pipe in front of the gas holder, a gas recovery main pipe in rear of the gas holder, and a control device. The first converter gas holder and the second converter gas holder are connected in parallel between the gas recovery main pipe in front of the gas holder and the gas recovery main pipe in rear of the gas holder, and the piston pressures of the two converter gas holders are close. At least one electric butterfly valve is installed on the inlet pipe of the first converter gas holder, and at least one electric butterfly valve is installed on the outlet pipe of the first converter gas holder; at least one piston position detection device is installed inside the first converter gas holder; the capacity of the first converter gas holder can be calculated by detecting the piston position.

[0026] At least one electric butterfly valve is installed on the inlet pipe of the second converter gas holder, and at least one electric butterfly valve is installed on the outlet pipe of the second converter gas holder; at least one piston position detection device is installed inside the second converter gas holder; the capacity of the second converter gas holder can be calculated by detecting the piston position.

[0027] The control device controls the opening or closing of the inlet electric butterfly valve based on the signals output by the piston position detection device of the first converter gas holder and the piston position detection device of the second converter gas holder, so as to keep the first converter gas holder or the second converter gas holder online.

[0028] Example 1 The present invention will be further described with reference to the accompanying drawings.

[0029] A domestic steel company has two converters and has successively built two converter gas holders, namely the first converter gas holder and the second converter gas holder, both with a capacity of 80,000 m³ / h. 3 The single-stage rubber diaphragm sealed gas holder has two gas holders operating at a pressure of approximately 2.5 kPa. The two gas holders operate on a one-in-one-out-of-service basis to avoid the release of converter gas during the maintenance of one converter gas holder.

[0030] The company's converter gas recovery system consists of a first converter gas holder (1), a second converter gas holder (2), a gas recovery main pipe in front of the holder (3), a gas recovery main pipe in back of the holder (4), a converter gas electrostatic precipitator (5), a converter gas pressurization station (6), and a control system. The first converter gas holder (1) and the second converter gas holder (2) are connected in parallel from the gas recovery main pipe in front of the holder (3) and the gas recovery main pipe in back of the holder (4). The gas recovery main pipe in back of the holder (4) is connected to the converter gas electrostatic precipitator (5) and then to the converter gas pressurization station (6). After purification and pressurization, the gas is delivered to the user. The inlet pipe (101) of the first converter gas holder is equipped with an electric butterfly valve (102), an electric blind flange valve (103), and a pneumatic quick-cut valve (104). The outlet pipe (105) of the first converter gas holder is equipped with a pneumatic quick-cut valve (106), an electric blind flange valve (107), and an electric butterfly valve (108). The first converter gas holder (1) is equipped with a piston position detection device, a piston speed detection device, a piston tilt detection device, a piston drift detection device, and a fixed CO alarm on the upper part of the piston. The inlet pipe (201) of the second converter gas holder is equipped with an electric butterfly valve (202), an electric blind flange valve (203), and a pneumatic quick-cut valve (204). The outlet pipe (205) of the second converter gas holder is equipped with a pneumatic quick-cut valve (206), an electric blind flange valve (207), and an electric butterfly valve (208). The second converter gas holder (2) is equipped with a piston position detection device, a piston speed detection device, a piston tilt detection device, a piston drift detection device, and a fixed CO alarm on the upper part of the piston. The piston position, piston speed, piston tilt, piston drift, and data measured by the fixed CO alarm on the upper part of the piston of the first and second converter gas holders are respectively linked with the electric butterfly valve (102) (202) and the pneumatic quick-cut valve (104) (204) on the gas inlet pipeline for protection, and are also linked with the pneumatic quick-cut valve (106) (206) and the electric butterfly valve (108) (208) on the gas outlet pipeline for protection. An oxygen content analyzer (301), gas temperature and gas pressure detectors are installed on the main gas pipe (3) in front of the gas holder. The gas holders of the first converter (1) and the second converter (2) share the same gas holder. The oxygen content analyzer (301) is interlocked with the electric butterfly valve (102) on the inlet pipe of the first converter gas holder and the electric butterfly valve (202) on the gas holder of the No. 2 converter. When the oxygen content exceeds 0.8%, a first-level alarm is triggered. When the oxygen content exceeds 1.0%, the electric butterfly valve (102 or 202) on the inlet pipe of the gas holder is closed. An oxygen content analyzer (401) is installed on the main gas pipe (4) behind the gas holder. It is shared by the first converter gas holder (1) and the second converter gas holder (2). The oxygen content analyzer (401) is interlocked with the electrostatic precipitator and the butterfly valve on the inlet pipe of the converter gas holder. When the oxygen content exceeds 0.8%, a first-level alarm is triggered. When the oxygen content exceeds 1.0%, the electric butterfly valve (102 or 202) on the inlet pipe of the gas holder is closed, and the electrostatic precipitator (5) automatically cuts off the high-voltage power supply. According to the appendix Figure 2When the first converter gas holder (1) is about to enter the maintenance state and the second converter gas holder (2) starts to recover gas, ① the piston, piston speed, piston tilt, piston drift, and the detection of the fixed CO alarm on the upper part of the piston set by the first and second converter gas holders are all within the normal range of the various interlocks, ensuring the inherent safety of the two converter gas holders; ② the system judges whether the current capacity of the first converter gas holder can meet the uninterrupted gas supply of the compressor within one smelting cycle, and meets the condition that after one smelting cycle, only gas is discharged and no gas is introduced, the capacity of the first converter gas holder is still not less than the low-level capacity interlock value. According to the calculation, V1 should not be less than 52000m 3 ③ Open the inlet butterfly valve (202) of the second converter gas holder and close the inlet butterfly valve (102) of the first converter gas holder to allow gas to enter the second converter gas holder and recover the gas of one smelting cycle; ④ Open the outlet butterfly valve (208) of the second converter gas holder and close the outlet butterfly valve (108) of the first converter gas holder. At this time, the online switching between the second converter gas holder and the first converter gas holder is completed. According to the appendix Figure 3 When the second converter gas holder (2) is about to enter the maintenance state and the first converter gas holder (1) starts to recover gas, ① both the first and second converter gas holders are within the normal range of various interlocks, ensuring the intrinsic safety of the two converter gas holders; ② the system determines whether the current capacity of the second converter gas holder can meet the uninterrupted gas supply of the compressor within one smelting cycle, and under the condition that gas is only discharged and not introduced after one smelting cycle, the capacity of the second converter gas holder is still not less than the low-level capacity interlock value. According to the calculation, V2 should not be less than 52000m³. 3 ; ③ Open the inlet butterfly valve (102) of the first converter gas holder and close the inlet butterfly valve (202) of the second converter gas holder to allow gas to enter the first converter gas holder and recover the gas of one smelting cycle; ④ Open the outlet butterfly valve (208) of the first converter gas holder and close the outlet butterfly valve (108) of the second converter gas holder. At this time, the online switching between the second converter gas holder and the first converter gas holder is completed.

[0031] The present invention has been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described above. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Many other changes and modifications made without departing from the concept and scope of the present invention should be considered within the scope of protection of the present invention.

[0032] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0033] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control system for online switching of dual converter gas holders, characterized in that, It includes a first converter gas holder, a second converter gas holder, a gas recovery main pipe in front of the gas holder, a gas recovery main pipe in rear of the gas holder, and a control device. The first converter gas holder and the second converter gas holder are connected in parallel between the gas recovery main pipe in front of the gas holder and the gas recovery main pipe in rear of the gas holder. At least one electric butterfly valve is installed on the inlet pipe of the first converter gas holder, and at least one electric butterfly valve is installed on the outlet pipe of the first converter gas holder; at least one piston position detection device is installed inside the first converter gas holder. At least one electric butterfly valve shall be installed on the inlet pipe of the second converter gas holder and at least one electric butterfly valve shall be installed on the outlet pipe of the second converter gas holder; at least one piston position detection device shall be installed inside the second converter gas holder. The control device controls the opening or closing of the inlet electric butterfly valve based on the signals output by the piston position detection device of the first converter gas holder and the piston position detection device of the second converter gas holder, so as to keep the first converter gas holder or the second converter gas holder online.

2. The control system for online switching of dual converter gas holders as described in claim 1, characterized in that, An inlet electric blind valve and an inlet pneumatic quick-cut valve are also provided on the inlet pipe of the first converter gas holder, and an outlet pneumatic quick-cut valve and an outlet electric blind valve are provided on the outlet pipe of the first converter gas holder.

3. The control system for online switching of dual converter gas holders as described in claim 1, characterized in that, The inlet pipe of the second converter gas holder is also equipped with an inlet electric blind valve and an inlet pneumatic quick-cut valve, and the outlet pipe of the second converter gas holder is equipped with an outlet pneumatic quick-cut valve and an outlet electric blind valve.

4. The control system for online switching of dual converter gas holders as described in claim 1, characterized in that, The first converter gas holder is also equipped with a piston speed detection device, a piston tilt detection device, a piston drift detection device, and a fixed CO alarm detection device on the upper part of the piston.

5. The control system for online switching of dual converter gas holders as described in claim 1, characterized in that, The second converter gas holder is also equipped with a piston speed detection device, a piston tilt detection device, a piston drift detection device, and a fixed CO alarm detection device on the upper part of the piston.

6. The control system for online switching of dual converter gas holders as described in claim 1, characterized in that, An oxygen content analyzer, a gas temperature detection device, and a gas pressure detection device are installed on the gas recovery main pipe in front of the cabinet.

7. The control system for online switching of dual converter gas holders as described in claim 1, characterized in that, An oxygen content analyzer is installed on the main gas pipe behind the cabinet.

8. The control system for online switching of dual converter gas holders as described in claim 1, characterized in that, A converter gas electrostatic precipitator and a converter gas pressurization station are sequentially installed at the outlet of the main gas recovery pipe after the cabinet.

9. A control method for online switching of dual converter gas holders, characterized in that, The method is implemented based on the system described in claim 1, and includes the following steps: Real-time monitoring of whether the current capacity of the online converter gas holder can meet the uninterrupted gas supply from the compressor within a smelting cycle, and whether the current capacity of the online converter gas holder is still not less than the low-level capacity interlock value under the condition that gas is only discharged and not introduced after a smelting cycle; If so, the inlet electric butterfly valve of the currently online converter gas holder should be closed first, and then the inlet electric butterfly valve of the currently offline converter gas holder should be opened to allow gas to enter the currently offline converter gas holder and recover gas for one smelting cycle. After a certain amount of gas has been recovered, the outlet electric butterfly valve of the currently offline converter gas holder should be opened and the outlet electric butterfly valve of the currently online converter gas holder should be closed. At this point, the online switching between the currently offline converter gas holder and the currently online converter gas holder is complete.

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