A safety control system and method for process operation of a coaxial unit

Abstract

This invention provides a process operation safety control system and method for a coaxial unit. When the turbine in the coaxial unit experiences a major fault shutdown, the blower stator control unit on the turbine interlocked blower and / or the anti-surge valve control unit on the blower interlocked reduces the angle of the blower stator by a safe adjustment angle compared to the angle of the blower stator during normal operation of the coaxial unit, and / or increases the opening of the anti-surge valve by a safe adjustment opening compared to the opening of the anti-surge valve during normal operation of the coaxial unit. This reduces the increase in motor load, allowing the blower to continue operating safely. This invention reduces the increase in motor load at the moment of turbine failure shutdown, ensuring a smooth transition of the unit and achieving a process operation safety control technology that allows the blower to continue operating even when the coaxial unit is shut down due to a major turbine fault, ensuring stable unit operation and production safety of the blast furnace ironmaking process system.

Description

Technical Field

[0001] This invention belongs to the field of turbo compressors and relates to coaxial units containing electric motors, specifically to a process operation safety control system and method for coaxial units. Background Technology

[0002] Blast furnace blowers are a crucial component of blast furnace production. With the development of blast furnace process energy recovery unit technology, coaxial units of blast furnace blowers and blast furnace gas pressure recovery turbines in blast furnace ironmaking systems have seen rapid development and application. This involves the motor and the blast furnace gas energy recovery turbine being arranged coaxially to jointly drive the blast furnace blower. The energy recovered by the turbine is directly used to drive the blower, reducing energy conversion steps and resulting in significant energy savings. This unit technology is now widely used. The motors are either asynchronous or synchronous, and the energy recovery turbine can be engaged and disengaged online within the unit.

[0003] The coaxial unit of the blast furnace blower and the blast furnace gas pressure turbine presents a risk of the gas turbine shutting down due to a serious malfunction during operation. This sudden increase in motor load can damage the motor or cause the unit to shut down, potentially leading to a safety accident in the blast furnace system. When the turbine suddenly trips due to a malfunction (with an action time of approximately 0.5 seconds), the load borne by the turbine must be compensated by the motor. This sudden increase in motor load has a significant impact on the motor's lifespan and safety. Especially for synchronous motors, with current technology, a 100% instantaneous load increase poses a risk of exciter overcurrent and motor malfunction. Electrical faults in the motor can lead to unit shutdown, affecting the production safety of the blast furnace ironmaking process system and even causing major process accidents, resulting in huge economic losses. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a safety control system and method for the process operation of coaxial units, so as to further improve the safety of the process operation of coaxial units.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for safe operation control of a coaxial unit, wherein the coaxial unit includes a blower, one end of which is coaxially connected to a motor via a gearbox, and the other end of which is coaxially connected to a turbine via a speed-changing clutch, wherein the motor and the turbine provide power to the blower; the method includes the following steps:

[0007] When the coaxial unit is operating normally, it operates according to the normal coaxial unit process, and the blower operates normally.

[0008] When the turbine in the coaxial unit fails and stops, the blower stator control unit on the turbine interlock blower reduces the angle of the blower stator by one blower stator safety adjustment angle based on the angle of the blower stator when the coaxial unit is running normally, thereby reducing the increase in motor load and ensuring that the blower continues to operate safely.

[0009] Alternatively, when the turbine in the coaxial unit fails and stops, the anti-surge valve control unit on the turbine interlocks with the blower, so that the opening of the anti-surge valve is increased by a safety adjustment opening on the basis of the opening of the anti-surge valve when the coaxial unit is running normally, thereby reducing the increase in motor load and the blower can still operate safely.

[0010] Alternatively, when the turbine in the coaxial unit fails and stops, the turbine interlocks both the blower stator control unit and the anti-surge valve control unit on the blower. This reduces the angle of the blower stator by a safe adjustment angle compared to the angle of the blower stator during normal operation of the coaxial unit, and increases the opening of the anti-surge valve by a safe adjustment angle compared to the opening of the anti-surge valve during normal operation of the coaxial unit. This reduces the increase in motor load, and the blower continues to operate safely.

[0011] The present invention also has the following technical features:

[0012] The safe adjustment angle of the blower's stationary blades is between 10 and 15°.

[0013] The safe adjustment opening of the anti-surge valve is between 5% and 10%.

[0014] The blower stator control unit includes a stator servo controller connected to the turbine. The input terminal of the stator servo controller is connected to a stator position transmitter installed on the stator servo cylinder. The output terminal of the stator servo controller is connected to an electro-hydraulic servo valve. The electro-hydraulic servo valve is connected to the stator servo cylinder. The stator servo cylinder drives the blower stator to adjust its angle.

[0015] The anti-surge valve control unit includes an anti-surge controller connected to the turbine. The input terminals of the anti-surge controller are connected to a differential pressure transmitter, a thermal resistor, and a pressure transmitter, respectively. The output terminal of the anti-surge controller is connected to the anti-surge valve. The differential pressure transmitter and the thermal resistor are installed on the inlet pipe of the compressor, and the pressure transmitter is installed on the outlet pipe of the compressor. The anti-surge valve is installed on an anti-surge pipeline parallel to the outlet pipe of the compressor.

[0016] The blower is an axial flow compressor.

[0017] The electric motor is either a synchronous motor or an asynchronous motor.

[0018] The turbine in question is a gas residual pressure turbine.

[0019] When there are multiple anti-surge valves, select one of the anti-surge valves with the largest diameter to add an anti-surge valve for safe adjustment of the opening.

[0020] This invention also protects a process operation safety control system for a coaxial unit, including a coaxial unit, wherein the coaxial unit includes a blower, one end of the blower is coaxially connected to a motor through a gearbox, and the other end of the blower is coaxially connected to a turbine through a speed-changing clutch, and the motor and the turbine provide power to the blower;

[0021] It also includes the blower stator control unit on the blower and the anti-surge valve control unit on the blower, with the turbine connected to the blower stator control unit and the anti-surge valve control unit respectively;

[0022] The blower stator control unit includes a stator servo controller connected to the turbine. The input terminal of the stator servo controller is connected to a stator position transmitter installed on the stator servo cylinder. The output terminal of the stator servo controller is connected to an electro-hydraulic servo valve. The electro-hydraulic servo valve is connected to the stator servo cylinder. The stator servo cylinder drives the blower stator to adjust its angle.

[0023] The anti-surge valve control unit includes an anti-surge controller connected to the turbine. The input terminals of the anti-surge controller are connected to a differential pressure transmitter, a thermal resistor, and a pressure transmitter, respectively. The output terminal of the anti-surge controller is connected to the anti-surge valve. The differential pressure transmitter and the thermal resistor are installed on the inlet pipe of the compressor, and the pressure transmitter is installed on the outlet pipe of the compressor. The anti-surge valve is installed on an anti-surge pipeline parallel to the outlet pipe of the compressor.

[0024] Compared with the prior art, the present invention has the following technical effects:

[0025] (I) This invention reduces the increase in motor load at the moment of turbine failure shutdown by interlocking blower stator blade control and anti-surge valve opening control, ensuring a smooth transition of the unit and realizing a process operation safety control technology that allows the blower to continue running even when the coaxial unit is shut down due to a severe turbine failure. This ensures the stable operation of the unit and the production safety of the blast furnace ironmaking process system.

[0026] (II) This invention, combining the process operation requirements of the blast furnace ironmaking system and through analysis and research on the performance and operating condition adjustment characteristics of the blast furnace blower, proposes a safety control technology for the process operation of a coaxial unit. As the core equipment of the blast furnace system, the blower must ensure continuous operation and avoid all possible risks that may cause blower shutdown, so as to ensure the stable operation of the blast furnace ironmaking process system.

[0027] (III) By reducing the stationary blade angle, the present invention can reduce the blower load. The load of the blast furnace blower can be reduced by about 15% during a failure. For the blast furnace system, the air volume is reduced, but the air pressure remains the same and will not affect the blast furnace system.

[0028] (IV) By increasing the opening of the anti-surge valve, the present invention can reduce the blower load. When the anti-surge valve is activated, the air volume entering the blast furnace system decreases and the air pressure will decrease, which will have a fluctuating effect on the blast furnace process, but will not cause damage to the blast furnace system.

[0029] (V) This invention avoids the risk of blower surge caused by a sudden reduction in the stator vane angle by both reducing the stator vane angle and increasing the anti-surge valve opening. This reduces the blast furnace blower load to 20%–25% of the load during a fault, and reduces the motor load from a 100% increase before turbine shutdown to a 50%–60% increase, significantly reducing the massive increase in motor load and mitigating the risk of motor failure and shutdown. This ensures both the safety of the motor equipment and the safe and continuous production of the blast furnace system. Attached Figure Description

[0030] Figure 1 This is a structural schematic diagram of a coaxial unit.

[0031] Figure 2 This is a schematic diagram of the structural design of the safety control system for the process operation of the coaxial unit.

[0032] The meanings of the labels in the diagram are as follows: 1-Blower, 2-Gearbox, 3-Electric motor, 4-Speed ​​change clutch, 5-Turbine, 6-Blower stator control unit, 7-Anti-surge valve control unit, 8-Blast furnace gas, 9-Air;

[0033] 101 - Inlet pipe, 102 - Outlet pipe, 103 - Anti-surge pipe;

[0034] 601-Stationary vane servo controller, 602-Stationary vane position transmitter, 603-Electro-hydraulic servo valve, 604-Stationary vane servo cylinder;

[0035] 701-Anti-surge controller, 702-Differential pressure transmitter, 703-Thermal resistance, 704-Pressure transmitter, 705-Anti-surge valve.

[0036] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0037] It should be noted that, unless otherwise specified, all devices and components in this invention are devices and components known in the prior art.

[0038] Following the above technical solutions, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0039] Example 1:

[0040] Following the above technical solution, this embodiment provides a process operation safety control system for coaxial units, such as... Figure 1 and Figure 2 As shown, it includes a coaxial unit, which includes a blower 1. One end of the blower 1 is coaxially connected to the motor 3 through a gearbox 2, and the other end of the blower 1 is coaxially connected to the turbine 5 through a speed-changing clutch 4. The motor 3 and the turbine 5 provide power to the blower 1.

[0041] It also includes the blower stator vane control unit 6 on the blower and the anti-surge valve control unit 7 on the blower, with the turbine 5 connected to the blower stator vane control unit 6 and the anti-surge valve control unit 7 respectively;

[0042] The blower stator control unit 6 includes a stator servo controller 601 connected to the turbine 5. The input terminal of the stator servo controller 601 is connected to the stator position transmitter 602 installed on the stator servo cylinder 604. The output terminal of the stator servo controller 601 is connected to the electro-hydraulic servo valve 603. The electro-hydraulic servo valve 603 is connected to the stator servo cylinder 604. The stator servo cylinder 604 drives the blower stator to adjust the angle.

[0043] The anti-surge valve control unit 7 includes an anti-surge controller 701 connected to the turbine 5. The input terminals of the anti-surge controller 701 are connected to a differential pressure transmitter 702, a thermal resistor 703, and a pressure transmitter 704, respectively. The output terminal of the anti-surge controller 701 is connected to an anti-surge valve 705. The differential pressure transmitter 702 and the thermal resistor 703 are installed on the inlet pipe 101 of the compressor 1, and the pressure transmitter 704 is installed on the outlet pipe 102 of the compressor 1. The anti-surge valve 705 is installed on an anti-surge pipe 103 parallel to the outlet pipe 102 of the compressor 1.

[0044] In this embodiment, preferably, the blower 1 is an axial flow compressor. The motor 3 is a synchronous electric motor or an asynchronous electric motor. The turbine 5 is a gas residual pressure turbine.

[0045] In this embodiment, the differential pressure transmitter 702 and the thermal resistor 703 are used for measuring the differential pressure at the compressor throat, and the thermal resistor 703 is used for measuring the temperature of the compressor inlet pipe; the pressure transmitter 704 is used for measuring the pressure of the compressor outlet pipe. The anti-surge valve 705 is used for emergency venting of the blower outlet pipe, and the anti-surge valve 705 has both good adjustment characteristics and a rapid full-opening function.

[0046] Example 2:

[0047] This embodiment provides a method for safe operation control of a coaxial unit, using the same coaxial unit as in Embodiment 1; the method includes the following steps:

[0048] When the coaxial unit is running normally, it operates according to the normal coaxial unit process, and blower 1 is running normally;

[0049] When turbine 5 in the coaxial unit fails and stops, the blower stationary blade control unit 6 on the interlock blower 1 of turbine 5 reduces the angle of the blower stationary blade by one blower stationary blade safety adjustment angle based on the angle of the blower stationary blade when the coaxial unit is running normally, thereby reducing the load increase of motor 3 and the blower 1 still operates safely.

[0050] In this embodiment, the blower stationary vane control unit 6 is the same as that in Embodiment 1.

[0051] In this embodiment, the safe adjustment angle of the blower's stationary blades is between 10 and 15°.

[0052] Example 3:

[0053] This embodiment provides a method for safe operation control of a coaxial unit, using the same coaxial unit as in Embodiment 1; the method includes the following steps:

[0054] When the coaxial unit is running normally, it operates according to the normal coaxial unit process, and blower 1 is running normally;

[0055] When turbine 5 in the coaxial unit fails and stops, the anti-surge valve control unit 7 on the turbine 5 interlocks with the blower 1, so that the opening of the anti-surge valve is increased by an anti-surge valve safety adjustment opening on the basis of the opening of the anti-surge valve when the coaxial unit is running normally, thereby reducing the increase in load on motor 3, and the blower 1 continues to operate safely.

[0056] In this embodiment, the anti-surge valve control unit 7 is the same as that in Embodiment 1.

[0057] In this embodiment, the anti-surge valve is safely adjusted to an opening of 5% to 10%.

[0058] In this embodiment, when there are multiple anti-surge valves, one of the anti-surge valves with the largest diameter is selected to add an anti-surge valve for safe adjustment of the opening.

[0059] Example 4:

[0060] This embodiment provides a method for safe operation control of a coaxial unit, using the same coaxial unit as in Embodiment 1; the method includes the following steps:

[0061] When the coaxial unit is running normally, it operates according to the normal coaxial unit process, and blower 1 is running normally;

[0062] When turbine 5 in the coaxial unit fails and stops, turbine 5 interlocks with both the blower stator control unit 6 on blower 1 and the anti-surge valve control unit 7 on blower 1. This causes the angle of the blower stator to be reduced by a safe adjustment angle based on the angle of the blower stator during normal operation of the coaxial unit, and the opening of the anti-surge valve to be increased by a safe adjustment opening based on the opening of the anti-surge valve during normal operation of the coaxial unit. This reduces the load increase on motor 3, and blower 1 continues to operate safely.

[0063] In this embodiment, the blower stationary vane control unit 6 is the same as that in Embodiment 1.

[0064] In this embodiment, the safe adjustment angle of the blower's stationary blades is between 10 and 15°.

[0065] In this embodiment, the anti-surge valve control unit 7 is the same as that in Embodiment 1.

[0066] In this embodiment, the anti-surge valve is safely adjusted to an opening of 5% to 10%.

[0067] In this embodiment, when there are multiple anti-surge valves, one of the anti-surge valves with the largest diameter is selected to add an anti-surge valve for safe adjustment of the opening.

[0068] It should be noted that the specific control method of the blower stator control unit 6 can adopt the conventional blower stator control method in this field.

[0069] It should be noted that the specific control method of the anti-surge valve control unit 7 can adopt the conventional anti-surge valve control method in this field.

[0070] It should be noted that before the turbine trips, the actual operating conditions are complex and variable. If stable operation cannot be achieved according to the preset parameters in Examples 2 to 4, the coaxial unit will enter its original protection system, surge protection or backflow protection, to achieve "safe operation" of the unit, and the blast furnace blower will switch out of the blast furnace air supply process, enter the minimum load, and run under venting conditions. At this time, manual operation can be performed immediately to switch back to the blast furnace system, restore the blast furnace air supply in a timely manner, and quickly achieve safe operation of the blast furnace system.

Claims

1. A method for safe control of process operation of a coaxial unit, wherein the coaxial unit includes a blower (1), one end of the blower (1) is coaxially connected to a motor (3) via a gearbox (2), and the other end of the blower (1) is coaxially connected to a turbine (5) via a speed-changing clutch (4), wherein the motor (3) and the turbine (5) provide power to the blower (1); the method includes the following steps: When the coaxial unit is running normally, it operates according to the normal coaxial unit process, and the blower (1) is running normally; The feature is that it also includes a blower stator control unit (6) on the blower and an anti-surge valve control unit (7) on the blower, and the turbine (5) is connected to the blower stator control unit (6) and the anti-surge valve control unit (7) respectively; The blower stator control unit (6) includes a stator servo controller (601) connected to the turbine (5). The input end of the stator servo controller (601) is connected to the stator position transmitter (602) installed on the stator servo cylinder (604). The output end of the stator servo controller (601) is connected to the electro-hydraulic servo valve (603). The electro-hydraulic servo valve (603) is connected to the stator servo cylinder (604). The stator servo cylinder (604) drives the blower stator to adjust the angle. The anti-surge valve control unit (7) includes an anti-surge controller (701) connected to the turbine (5). The input terminals of the anti-surge controller (701) are connected to a differential pressure transmitter (702), a thermal resistor (703), and a pressure transmitter (704), respectively. The output terminal of the anti-surge controller (701) is connected to an anti-surge valve (705). The differential pressure transmitter (702) and the thermal resistor (703) are installed on the inlet pipe (101) of the blower (1), and the pressure transmitter (704) is installed on the outlet pipe (102) of the blower (1). The anti-surge valve (705) is installed on an anti-surge pipe (103) parallel to the outlet pipe (102) of the blower (1). When the turbine (5) in the coaxial unit fails and stops, the blower stationary blade control unit (6) on the turbine (5) interlocks the blower (1) so that the angle of the blower stationary blade is reduced by one blower stationary blade safety adjustment angle based on the angle of the blower stationary blade when the coaxial unit is running normally, thereby reducing the load increase of the motor (3) and the blower (1) still runs safely. Or when the turbine (5) in the coaxial unit fails and stops, the anti-surge valve control unit (7) on the turbine (5) interlocks with the blower (1) to make the opening of the anti-surge valve increase by an anti-surge valve safety adjustment opening based on the opening of the anti-surge valve when the coaxial unit is running normally, thereby reducing the increase in load on the motor (3) and the blower (1) still runs safely; Or when the turbine (5) in the coaxial unit fails and stops, the turbine (5) interlocks the blower stator control unit (6) on the blower (1) and the anti-surge valve control unit (7) on the blower (1), so that the angle of the blower stator is reduced by a blower stator safety adjustment angle based on the angle of the blower stator when the coaxial unit is running normally, and the opening of the anti-surge valve is increased by an anti-surge valve safety adjustment opening based on the opening of the anti-surge valve when the coaxial unit is running normally, thereby reducing the increase in load of the motor (3) and the blower (1) still runs safely; The safe adjustment angle of the blower stator blades is between 10° and 15°. The safe adjustment opening of the anti-surge valve is between 5% and 10%. The blower (1) is an axial flow compressor; The turbine (5) mentioned above is a gas residual pressure turbine; When there are multiple anti-surge valves, select one of the anti-surge valves with the largest diameter to add an anti-surge valve for safe adjustment of the opening.

2. The method for safe operation control of coaxial unit processes as described in claim 1, characterized in that, The electric motor (3) is a synchronous electric motor or an asynchronous electric motor.

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