Structure and method for realizing redundancy of electromagnetic valve and control loop by pregnant solution pneumatic stop valve of blast furnace gas decarburization system

Abstract

The invention belongs to the technical field of control loop redundancy, and particularly discloses a structure for realizing electromagnetic valve and control loop redundancy of a pregnant solution pneumatic stop valve of a blast furnace gas decarbonization system, which comprises a gas storage tank and an absorption tower, a pressure gauge and a pressure transmitter are arranged on the gas storage tank, and a regulating valve is arranged on a pipeline at the gas outlet end of the gas storage tank. The gas outlet end of the gas storage tank is connected with two electromagnetic valves in parallel, the absorption tower is communicated with a flash tank, a rich liquid pneumatic cut-off valve is arranged on a pipeline for communicating the absorption tower with the flash tank, and a control cylinder of the rich liquid pneumatic cut-off valve is connected with one electromagnetic valve. In order to solve the problem that a system is stopped by mistake due to the fact that the rich liquid pneumatic cut-off valve loses a control signal, redundancy protection of the rich liquid pneumatic cut-off valve is achieved through the redundancy design of the double electromagnetic valves and the double control loops, and the problem that in the prior art, control loop faults are caused by electromagnetic valve faults or control cable breakage is solved. The problems that the rich liquid pneumatic stop valve loses a control signal, valve misoperation is caused, and a system is stopped by mistake are solved.

Description

Technical Field

[0001] This invention relates to the field of control loop redundancy technology, specifically to a structure and method for achieving solenoid valve and control loop redundancy in a liquid-rich pneumatic shut-off valve of a blast furnace gas decarbonization system. Background Technology

[0002] In the blast furnace gas decarbonization system of the iron and steel metallurgical industry, the rich liquid pneumatic shut-off valve is a core and critical piece of equipment to ensure the safe operation of the process, and its operational reliability is directly related to the inherent safety level of the system. As an important link in the purification and recovery of blast furnace gas, the decarbonization process needs to operate continuously under high temperature, high pressure, and highly corrosive media conditions. The media within the system often possess flammable, explosive, toxic, and harmful properties. Once media leakage or abnormal pressure occurs, it can lead to serious consequences such as fires, explosions, equipment damage, and even personal injury or death.

[0003] Currently, key interlocking pneumatic shut-off valves in blast furnace gas decarbonization systems typically employ either air-to-open or air-to-close valves. Air-to-open valves automatically and quickly close when the control gas source or control signal is lost. Their core function is to prevent the continuous entry of hazardous media into the system, thus avoiding a safety accident and preventing the escalation of dangerous conditions. They are widely used in scenarios involving the interruption of critical media, such as rich liquid transportation and gas channels. Air-to-close valves, on the other hand, automatically and quickly open when the control gas source or control signal is lost. Their core function is to promptly introduce protective media or relieve system pressure, ensuring equipment safety under abnormal operating conditions. They are typically used in pressure buffering or safety pressure relief circuits.

[0004] Currently, the control of the rich-liquid pneumatic shut-off valve in the blast furnace gas decarbonization system generally adopts the traditional structure of a single solenoid valve and a single control loop. Its working principle is as follows: the PLC controller sends an electrical signal to the solenoid valve through a single control loop. Upon receiving the power, the solenoid valve drives the pneumatic actuator, thereby opening or closing the valve. However, this structure is highly susceptible to malfunction of the rich-liquid pneumatic shut-off valve in the steel smelting environment, leading to unplanned system shutdowns and affecting production continuity. The main reasons are: firstly, the blast furnace production site experiences strong electromagnetic interference, dust pollution, and vibration impacts. Over long-term operation, the solenoid valve core is prone to jamming, wear, or coil burnout. When the solenoid valve experiences a power failure, it loses control of the pneumatic actuator, and the valve automatically closes under the spring's restoring force; if the solenoid valve experiences coil sticking, the valve cannot close properly, and in severe cases, it may directly trigger a system-wide shutdown. Secondly, most of the existing control circuit signal transmission cables are laid in a single path, which is easily affected by on-site mechanical damage and electromagnetic interference, resulting in faults such as signal distortion. When a short circuit occurs in the control circuit, the instructions issued by the PLC controller cannot be transmitted to the solenoid valve, and the valve is in an uncontrolled state. When the control circuit is subjected to electromagnetic interference, false electrical signals will be generated, which will mislead the solenoid valve to perform incorrect actions. For example, the valve may be accidentally triggered to close during normal system operation, causing the rich liquid delivery to be interrupted, and the decarbonization system will be forced to shut down for maintenance.

[0005] In summary, it is necessary to design a device and method for achieving redundancy of solenoid valves and control circuits in the rich liquid pneumatic shut-off valve of the blast furnace gas decarbonization system. This is to solve the problem that under the existing technology, the rich liquid pneumatic shut-off valve loses control signal due to solenoid valve failure or control cable breakage, which leads to valve malfunction and system shutdown. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for achieving redundancy of solenoid valves and control circuits in the rich liquid pneumatic shut-off valve of a blast furnace gas decarbonization system, so as to solve the problem in the prior art where the rich liquid pneumatic shut-off valve loses control signal due to solenoid valve failure or control cable breakage, thereby causing valve malfunction and system shutdown.

[0007] To achieve the above objectives, the basic solution provided by this invention is as follows: a structure for a rich liquid pneumatic shut-off valve in a blast furnace gas decarbonization system to achieve redundancy of solenoid valves and control circuits, comprising a gas storage tank and an absorption tower, wherein the gas storage tank is equipped with a pressure gauge and a remote pressure transmitter, a flow regulating valve is provided on the pipeline at the gas outlet of the gas storage tank, and solenoid valve one and solenoid valve two are connected in parallel at the gas outlet of the gas storage tank, a flash tank is connected to the absorption tower, and a rich liquid pneumatic shut-off valve is provided on the pipeline connecting the absorption tower and the flash tank, wherein the control cylinder of the rich liquid pneumatic shut-off valve is connected to solenoid valve one.

[0008] The beneficial effects of the present invention are as follows: (1) The present invention uses a redundant design of dual solenoid valves and dual control circuits. When both solenoid valves lose power at the same time, the rich liquid pneumatic shut-off valve will close. A single solenoid valve failure or a single PLC controller output failure will not cause the valve to malfunction. This achieves a significant improvement in the continuity and stability of the production process and reduces economic losses caused by accidental shutdowns while ensuring safety interlocking. (2) By connecting two two-position three-way solenoid valves, when any solenoid valve loses power due to a failure, the air source can continue to supply air to the control cylinder of the rich liquid pneumatic shut-off valve through another normally energized solenoid valve, so that the valve remains in its original state and the production process is not affected. (3) The redundant control circuit structure in the present invention only requires adding one solenoid valve to the original control circuit to achieve redundant protection of key valves. This reduces the investment in equipment costs while ensuring process interlocking safety.

[0009] Option 2, which is a preferred option of the basic option, is provided with a one-way valve on the pipeline connecting the gas storage tank and the gas source. The one-way valve can prevent compressed gas from flowing back from the gas storage tank to the gas source, ensuring the pressure inside the gas storage tank is stable, thereby providing reliable power to the system. At the same time, it can also isolate the gas storage tank when the gas source fails or the pressure drops, thereby maintaining the gas pressure required for short-term operation of the system.

[0010] Option 3, which is a preferred option of the basic option, is that both solenoid valve 1 and solenoid valve 2 are two-position three-way solenoid valves. Both solenoid valve 1 and solenoid valve 2 include an air source inlet A, an air source outlet B, and a pressure relief port C. The air source outlet B of solenoid valve 1 is connected to the air inlet of the control cylinder of the rich liquid pneumatic shut-off valve, and the air source inlet A of solenoid valve 2 is connected to the air outlet of the air storage tank.

[0011] Option 4, which is a preferred option of the basic option, includes two PLC controllers, an intermediate relay, and a contact switch in the control circuit of solenoid valve one and solenoid valve two. Solenoid valve one and solenoid valve two are connected in series with the PLC controllers and the intermediate relay. The two solenoid valves are controlled by two PLC controllers respectively. Even if one PLC controller fails, it can still be controlled by the other controller to ensure that the signal command is not interrupted.

[0012] Option 5, a method for achieving redundancy of solenoid valves and control circuits in a liquid-rich pneumatic shut-off valve of a blast furnace gas decarbonization system, characterized by the following steps: S1: When it is necessary to open the rich liquid pneumatic shut-off valve, firstly, solenoid valve one and solenoid valve two are energized at the same time. Then, the flow regulating valve is opened so that the gas in the gas storage tank enters the gas source input port A of solenoid valve one and solenoid valve two through the pipeline respectively. Then, the gas entering the gas source input port A of solenoid valve one is output from the gas source output port B of solenoid valve one and enters the air inlet of the control cylinder of the rich liquid pneumatic shut-off valve. Then, by controlling the cylinder, the rich liquid pneumatic shut-off valve can be opened so that the rich liquid in the absorption tower enters the flash tank through the rich liquid pneumatic shut-off valve for flash separation. S2: When it is necessary to close the rich liquid pneumatic shut-off valve, solenoid valve one and solenoid valve two are de-energized at the same time. At this time, the air source of the control cylinder of the rich liquid pneumatic shut-off valve enters the air source output port B of solenoid valve one through the pressure relief port C of solenoid valve one, and finally exits from the pressure relief port C of solenoid valve two. This means that the control cylinder loses air, and the rich liquid pneumatic shut-off valve is closed. When the flooded pneumatic shut-off valve closes, it ensures that the gas in the control cylinder can be quickly and completely emptied through a specific exhaust path, thus ensuring that the flooded pneumatic shut-off valve closes.

[0013] Option 6, an optimal choice of Option 5, involves the following steps: In S1, the gas entering the gas input port A of solenoid valve 2 is output through the gas output port B of solenoid valve 2 and then stored in the pressure relief port C of solenoid valve 1 for backup. When solenoid valve 1 loses power, the backup gas in the pressure relief port C of solenoid valve 1 is output through the gas output port B of solenoid valve 1 to supply gas to the control cylinder of the rich liquid pneumatic shut-off valve. This achieves redundancy for a single point of failure of solenoid valve 1. When solenoid valve 1 fails, the stored gas can take over the gas supply, ensuring that the rich liquid pneumatic shut-off valve will not close accidentally, thus guaranteeing the continuity of the process. Furthermore, it eliminates the need for additional gas storage tanks or valves, achieving the backup gas source function solely through pipeline connections, resulting in lower costs.

[0014] Option 7, a preferred option of Option 5, in S1, when solenoid valve 2 is de-energized and solenoid valve 1 is energized, the gas in the gas storage tank enters the gas source input port A of solenoid valve 1 and is delivered to the control cylinder of the rich liquid pneumatic shut-off valve through the gas source output port B of solenoid valve 1 to supply gas, thereby enabling the rich liquid pneumatic shut-off valve to open normally. At the same time, the spare gas in the pressure relief port C of solenoid valve 1 is discharged from the pressure relief port C of solenoid valve 2 through the gas source output port B of solenoid valve 2. When solenoid valve 2 malfunctions, it can vent the gas in its branch, avoiding interference or causing the rich liquid pneumatic shut-off valve to malfunction, while not affecting the normal operation of the system and avoiding unplanned shutdowns. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a liquid-rich pneumatic shut-off valve in a blast furnace gas decarbonization system to achieve redundancy of the solenoid valve and control circuit. Figure 2This is a schematic diagram of the control circuit principle of a method for achieving redundancy of solenoid valve and control circuit in a liquid-rich pneumatic shut-off valve of a blast furnace gas decarbonization system according to the present invention. Detailed Implementation

[0016] The present invention will be further described in detail below through specific embodiments: The accompanying drawings in the instruction manual include: 1. Gas storage tank; 2. Absorption tower; 3. Pressure gauge; 4. Remote pressure transmitter; 5. Flow regulating valve; 6. Solenoid valve one; 7. Solenoid valve two; 8. Flash tank; 9. Rich liquid pneumatic shut-off valve; 10. Check valve; 11. Intermediate relay.

[0017] Example like Figure 1 and Figure 2 As shown, a structure for a redundant solenoid valve and control circuit of a rich liquid pneumatic shut-off valve in a blast furnace gas decarbonization system includes a gas storage tank 1 and an absorption tower 2. A one-way valve 10 is installed on the pipeline connecting the gas storage tank 1 to the gas source. A pressure gauge 3 and a remote pressure transmitter 4 are installed on the gas storage tank 1. A flow regulating valve 5 is installed on the pipeline at the gas outlet of the gas storage tank 1. A solenoid valve 6 and a solenoid valve 7 are connected in parallel at the gas outlet of the gas storage tank 1. Both solenoid valves 6 and 7 are two-position three-way solenoid valves. Both solenoid valves 6 and 7 include a gas source inlet A, a gas source outlet B, and a pressure relief port. C. The gas source output port B of solenoid valve 2 7 is connected to the pressure relief port C of solenoid valve 1 6. A flash tank 8 is connected to the absorption tower 2. A rich liquid pneumatic shut-off valve 9 is installed on the pipeline connecting the absorption tower 2 and the flash tank 8. The air inlet of the control cylinder of the rich liquid pneumatic shut-off valve 9 is connected to the gas source output port B of solenoid valve 1 6. The control circuit of solenoid valve 1 6 and solenoid valve 2 7 includes two PLC controllers, intermediate relay 11 and contact switch. Solenoid valve 1 6 and solenoid valve 2 7 are connected in series with the PLC controllers and intermediate relay 11. The external power supply of the two PLC controllers is 24V.

[0018] Based on the aforementioned structure for achieving solenoid valve and control circuit redundancy in the rich-liquid pneumatic shut-off valve of the blast furnace gas decarbonization system, a method for achieving solenoid valve and control circuit redundancy in the rich-liquid pneumatic shut-off valve of the blast furnace gas decarbonization system is provided, specifically including the following steps: S1: When it is necessary to open the rich liquid pneumatic shut-off valve 9, firstly, solenoid valve 6 and solenoid valve 7 are energized simultaneously. Then, the flow regulating valve 5 is opened so that the gas in the gas storage tank 1 enters the gas source inlet A of solenoid valve 6 and solenoid valve 7 through the pipeline. Then, the gas entering the gas source inlet A of solenoid valve 6 is output from the gas source outlet B of solenoid valve 6 and enters the inlet end of the control cylinder of the rich liquid pneumatic shut-off valve 9. Then, by controlling the cylinder, the rich liquid pneumatic shut-off valve 9 can be opened so that the rich liquid in the absorption tower 2 enters the flash tank 8 through the rich liquid pneumatic shut-off valve 9 for flash separation. At this time, the gas entering the gas source inlet A of solenoid valve 7 is output from the gas source outlet B of solenoid valve 7 and enters the pressure relief port C of solenoid valve 6 for storage and standby. S2: When it is necessary to close the rich liquid pneumatic shut-off valve 9, solenoid valve 6 and solenoid valve 7 are de-energized at the same time. At this time, the air source of the control cylinder of the rich liquid pneumatic shut-off valve 9 enters the air source output port B of solenoid valve 1 through the pressure relief port C of solenoid valve 1, and finally exits from the pressure relief port C of solenoid valve 7. This means that the control cylinder loses air and the rich liquid pneumatic shut-off valve 9 is closed. S3: When solenoid valve 6 is de-energized and solenoid valve 7 is energized, the gas in the gas storage tank 1 enters the gas source input port A of solenoid valve 7, exits through the gas source output port B of solenoid valve 7, enters the pressure relief port C of solenoid valve 6, and then exits through the gas source output port B of solenoid valve 6 to supply air to the control cylinder of the rich liquid pneumatic shut-off valve 9, thereby opening the rich liquid pneumatic shut-off valve 9; when solenoid valve 7 is de-energized and solenoid valve 6 is energized, the gas in the gas storage tank 1 enters the gas source input port A of solenoid valve 6, passes through the gas source output port B of solenoid valve 6 and is delivered to the control cylinder of the rich liquid pneumatic shut-off valve 9 to supply air, thereby opening the rich liquid pneumatic shut-off valve 9 normally, and at the same time, the spare gas in the pressure relief port C of solenoid valve 6 is discharged through the gas source output port B of solenoid valve 7 from the pressure relief port C of solenoid valve 7.

[0019] In summary, by configuring redundant dual solenoid valves and dual control loops for the rich-liquid pneumatic shut-off valve, not only is valve malfunction caused by the failure of a single solenoid valve or control loop effectively prevented, but the system's availability and intrinsic safety are also significantly improved. Furthermore, by connecting the air supply output port of one solenoid valve to the pressure relief port of the other, and combining this with a completely independent control strategy for power supply and control signals, a fail-safe mechanism for the pneumatic shut-off valve is implemented. The valve only activates when both solenoid valves simultaneously receive and execute interlock commands. Ultimately, while ensuring reliable process safety interlocks, this significantly reduces the risk of unplanned shutdowns and equipment investment costs.

[0020] 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 and improvements 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 structure for achieving redundancy of solenoid valves and control circuits in a rich-liquid pneumatic shut-off valve of a blast furnace gas decarbonization system, characterized in that, The system includes a gas storage tank (1) and an absorption tower (2). The gas storage tank (1) is equipped with a pressure gauge (3) and a remote pressure transmitter (4). A flow regulating valve (5) is provided on the pipeline at the gas outlet of the gas storage tank (1). A solenoid valve one (6) and a solenoid valve two (7) are connected in parallel at the gas outlet of the gas storage tank (1). A flash tank (8) is connected to the absorption tower (2). A rich liquid pneumatic shut-off valve (9) is provided on the pipeline connecting the absorption tower (2) and the flash tank (8). The control cylinder of the rich liquid pneumatic shut-off valve (9) is connected to the solenoid valve one (6).

2. The structure of the rich liquid pneumatic shut-off valve in the blast furnace gas decarbonization system according to claim 1, which achieves redundancy of the solenoid valve and control circuit, is characterized in that... A one-way valve (10) is provided on the pipeline connecting the gas storage tank (1) to the gas source.

3. The structure of the rich liquid pneumatic shut-off valve in the blast furnace gas decarbonization system according to claim 1, which achieves redundancy of the solenoid valve and control circuit, is characterized in that... Both solenoid valve one (6) and solenoid valve two (7) are two-position three-way solenoid valves. Both solenoid valve one (6) and solenoid valve two (7) include an air source inlet A, an air source outlet B and a pressure relief port C. The air source outlet B of solenoid valve one (6) is connected to the air inlet of the control cylinder of the rich liquid pneumatic shut-off valve (9), and the air source inlet A of solenoid valve two (7) is connected to the air outlet of the gas storage tank (1).

4. The structure of the rich liquid pneumatic shut-off valve in the blast furnace gas decarbonization system according to claim 1, which achieves redundancy of the solenoid valve and control circuit, is characterized in that... The control circuit of the solenoid valve one (6) and solenoid valve two (7) includes two PLC controllers, an intermediate relay (11) and a contact switch. The solenoid valve one (6) and solenoid valve two (7) are connected in series with the PLC controller and the intermediate relay (11).

5. A method for achieving redundancy of solenoid valves and control circuits in a rich-liquid pneumatic shut-off valve of a blast furnace gas decarbonization system, characterized in that... Includes the following steps: S1: When it is necessary to open the rich liquid pneumatic shut-off valve (9), firstly, solenoid valve one (6) and solenoid valve two (7) are energized at the same time, and then the flow regulating valve (5) is opened so that the gas in the gas storage tank (1) enters the gas source input port A of solenoid valve one (6) and solenoid valve two (7) through the pipeline respectively. Then, the gas entering the gas source input port A of solenoid valve one (6) is output from the gas source output port B of solenoid valve one (6) and enters the gas inlet end of the control cylinder of the rich liquid pneumatic shut-off valve (9). Then, by controlling the cylinder, the rich liquid pneumatic shut-off valve (9) can be opened so that the rich liquid in the absorption tower (2) enters the flash tank (8) through the rich liquid pneumatic shut-off valve (9) for flash separation. S2: When it is necessary to close the rich liquid pneumatic shut-off valve (9), solenoid valve one (6) and solenoid valve two (7) are de-energized at the same time. At this time, the air source of the control cylinder of the rich liquid pneumatic shut-off valve (9) enters the air source output port B of solenoid valve one through the air source output port C of solenoid valve one, and finally exits from the air source output port C of solenoid valve two (7). This means that the control cylinder loses air and the rich liquid pneumatic shut-off valve (9) is closed.

6. The method for achieving redundancy of the solenoid valve and control circuit in the rich liquid pneumatic shut-off valve of a blast furnace gas decarbonization system according to claim 5, characterized in that, In S1, the gas entering the gas source input port A of solenoid valve two (7) is output through the gas source output port B of solenoid valve two (7) and then enters the pressure relief port C of solenoid valve one (6) for storage and standby; when solenoid valve one (6) loses power, the standby gas source in the pressure relief port C of solenoid valve one (6) is output through the gas source output port B of solenoid valve one (6) to supply gas to the control cylinder of the rich liquid pneumatic shut-off valve (9).

7. The method for achieving redundancy of the solenoid valve and control circuit in the rich liquid pneumatic shut-off valve of a blast furnace gas decarbonization system according to claim 5, characterized in that, In S1, when solenoid valve 2 (7) is de-energized and solenoid valve 1 (6) is energized, the gas in the gas storage tank (1) enters the gas source input port A of solenoid valve 1 (6) and is delivered to the control cylinder of the rich liquid pneumatic shut-off valve (9) through the gas source output port B of solenoid valve 1 (6) to supply gas, thereby making the rich liquid pneumatic shut-off valve (9) open normally. At the same time, the spare gas in the pressure relief port C of solenoid valve 1 (6) is discharged from the pressure relief port C of solenoid valve 2 (7) through the gas source output port B of solenoid valve 2 (7).

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