Oxygen header pipe stop valve interlocking system

Abstract

The utility model discloses an oxygen main pipe cut-off valve interlocking system, an SIS control system is connected with an oxygen main pipe cut-off valve through a second electromagnetic three-way valve and a third electromagnetic three-way valve and a limit switch, and the oxygen main pipe cut-off valve is respectively connected with an oxygen main pipe and a detection device; the SIS control system is connected with the detection device through a nitrogen cut-off valve and a check valve; and the limit switch and the pressure detection device are connected with the SIS control system. The SIS control system is used for controlling the oxygen header pipe stop valve and the nitrogen stop valve respectively, it is guaranteed that only one stop valve can be opened after being closed in place, meanwhile, the pressure detection devices are arranged in front of and behind the oxygen header pipe stop valve respectively, and it is guaranteed that a certain pressure difference exists in front of and behind the oxygen header pipe stop valve; safety accidents such as fire disasters and explosion caused by too high oxygen flow velocity at the moment of valve opening are avoided, and system safety is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of oxygen control of gasifiers, and in particular relates to an oxygen main pipe cut-off valve interlocking system. Background Art

[0002] The coal gasification process is a process that uses high-purity oxygen as a gasifying agent to convert the carbon in the coal into a synthesis gas with the main components of CO and H2 to the maximum extent. It is generally produced by the high-pressure, high-purity oxygen (99.6%) produced by the air separation unit and sent to the gasifier process burner through the oxygen pipeline to partially react with water-coal slurry or coal powder. The high-pressure and high-speed combustion in the gasifier requires a large amount of oxygen. In order to ensure the safety of the gasifier, the oxygen flow must be strictly controlled. The requirements for both regulation and cut-off functions are very high. Usually three control valves are selected to complete it, namely oxygen flow control valve, oxygen cut-off control valve, oxygen venting control valve, collectively referred to as oxygen control valve, which is a control valve with special application requirements among industrial process control valves.

[0003] The existing design of oxygen main control valve and high-pressure nitrogen control valve signals entering the DCS system has the following defects: 1. Insufficient safety level: The DCS system is mainly used for process control and does not have the high safety level of SIS. The SIS system has higher safety integrity and reliability requirements. Therefore, connecting the oxygen main control valve signal only to the DCS system may not meet the strict requirements for safety. 2. Slow response speed: Although the DCS system can perform real-time monitoring and control, its design and optimization often focus more on process control rather than rapid response to emergency safety events. In contrast, the SIS system has a faster response speed and higher reliability, and can respond within milliseconds to prevent potential dangerous situations. 3. Limited interlocking logic: The DCS system may not support complex interlocking logic, or its interlocking logic implementation is not as flexible and reliable as the SIS system. For oxygen main control valves that require precise control and rapid response, relying solely on the DCS system may not be able to achieve the required safety protection functions. 4. Limited fault isolation and diagnosis capabilities: Although the DCS system has basic fault diagnosis capabilities, it may not be as good as the SIS system in handling complex safety events and fault isolation. SIS systems are usually equipped with higher-level fault diagnosis and event recording functions to help quickly identify and resolve potential safety issues. 5. There is no interlocking logic between the high-pressure nitrogen control valve and the oxygen main shut-off valve. When the nitrogen pressure is lower than the oxygen pressure, the oxygen flow rate is too high when the oxygen shut-off valve opens, which may increase the risk of fire or explosion. Too fast a flow rate may cause oxygen to mix fully with combustibles, which may cause an explosion or fire once it encounters a fire source. Utility Model Content

[0004] In view of the above technical problems, the utility model provides an oxygen main shut-off valve interlocking system, which utilizes the SIS control system to control the oxygen main shut-off valve, the nitrogen shut-off valve, the pressure deviation relay and multiple electromagnetic three-way valves to achieve the interlocking of high-purity oxygen and high-pressure nitrogen, ensuring that when the nitrogen pressure is lower than the oxygen pressure, the oxygen main shut-off valve cannot be opened, thereby improving the safety of the system.

[0005] In order to achieve the above-mentioned purpose, the utility model provides an oxygen main shut-off valve interlocking system, wherein the SIS control system is connected to the oxygen main shut-off valve via a second electromagnetic three-way valve and a third electromagnetic three-way valve and a limit switch, and the oxygen main shut-off valve is respectively connected to the oxygen main and a detection device; the SIS control system is connected to the detection device via a nitrogen shut-off valve and a check valve; the limit switch and the pressure detection device are connected to the SIS control system.

[0006] Preferably, the detection device includes a temperature monitoring device and a pressure detection device; the temperature monitoring device includes a temperature detector, a temperature indicating alarm and a temperature driver connected in sequence; the pressure detection device includes a second pressure signal transmitter, a second pressure indicating alarm, a pressure driver, a pressure deviation relay and a pressure deviation indicating alarm connected in sequence.

[0007] Further preferably, the pressure deviation relay is connected to a SIS control system.

[0008] Preferably, the SIS control system is connected to the nitrogen cut-off valve via the first electromagnetic three-way valve, and the nitrogen cut-off valve is connected to the second ball valve.

[0009] Preferably, the pipeline between the oxygen main shut-off valve and the oxygen main is connected to the first pressure signal transmitter via a first ball valve, and the first pressure signal transmitter is connected to the first pressure driver and the first pressure indicating alarm respectively.

[0010] Further preferably, the first pressure driver is connected to the pressure deviation relay via a system internal signal transmission line.

[0011] The beneficial effects of the utility model are:

[0012] 1. Use the SIS control system to control multiple electromagnetic shut-off valves, limit switches, oxygen main shut-off valves and nitrogen shut-off valves, so that the valves controlling oxygen and the valves controlling nitrogen are interlocked with each other, ensuring that the valve or switch on one side can be opened only after the valve or switch on the other side is fully closed, ensuring that the oxygen in the system is maintained at an appropriate pressure and flow rate, avoiding excessive oxygen flow rate at the moment of valve opening, resulting in full mixing of oxygen and combustibles, and safety accidents such as fire or explosion after encountering a fire source, thereby improving system safety.

[0013] 2. Install pressure detection devices and temperature monitoring devices before and after the oxygen main shut-off valve to maintain a certain pressure difference before and after the oxygen main shut-off valve. A The oxygen main shut-off valve can only be opened when this happens to avoid safety accidents caused by excessive oxygen flow at the moment of opening.

[0014] 3. The SIS control system is used to achieve precise control and rapid response of multiple valves, support the interlocking logic of multiple valves, and at the same time improve the ability to handle complex safety events and fault isolation, quickly identify and resolve potential safety issues, and improve overall safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a schematic diagram of the structure of the utility model, in which 1 is a SIS control system, 2 is a limit switch, 3 is a first pressure signal transmitter, 4 is a second pressure signal transmitter, 5 is a pressure deviation indicating alarm, 6 is an oxygen main shut-off valve, 7 is a nitrogen shut-off valve, 8 is an oxygen main, 9 is a first ball valve, 10 is a first pressure driver, 11 is a first pressure indicating alarm, 12 is a check valve, 13 is a second ball valve, 14 is a temperature detector, 15 is a first electromagnetic three-way valve, 16 is a second electromagnetic three-way valve, 17 is a third electromagnetic three-way valve, 18 is a temperature indicating alarm, 19 is a temperature driver, 20 is a second pressure indicating alarm, 21 is a pressure driver, and 22 is a pressure deviation relay. DETAILED DESCRIPTION

[0016] The technical solution of the utility model is further explained below in conjunction with the accompanying drawings and specific embodiments. It is worth noting that the following embodiments are only preferred embodiments of the utility model and should not be understood as limiting the utility model. The protection scope of the utility model shall be based on the content recorded in the claims. Any modification or replacement made by a person skilled in the art to the technical solution of the utility model without creative work shall fall within the protection scope of the utility model.

[0017] Example 1

[0018] like Figure 1As shown, an oxygen main shut-off valve interlocking system, the SIS control system 1 generates a control signal, supplies power to the second electromagnetic three-way valve 16 and the third electromagnetic three-way valve 17, and then transmits the control signal to the limit switch 2 to control its opening or closing. The limit switch 2 is connected to the oxygen main shut-off valve 6 to further control the shut-off and opening states of the oxygen main shut-off valve 6. The oxygen main shut-off valve 6 is respectively connected to the oxygen main 8 and the detection device; the SIS control system 1 is connected to the detection device via the nitrogen shut-off valve 7 and the check valve 12 to control the shut-off and opening devices of the nitrogen shut-off valve 7; the limit switch 2 and the pressure detection device are respectively connected to the SIS control system 1, and the state of the executed signal is returned to the SIS control system 1 to determine whether the execution is in place.

[0019] Preferably, the detection device includes a temperature monitoring device and a pressure detection device; the temperature monitoring device includes a temperature detector 14, a temperature indicating alarm 18 and a temperature driver 19 connected in sequence; the pressure detection device includes a second pressure signal transmitter 4, a second pressure indicating alarm 20, a pressure driver 21, a pressure deviation relay 22 and a pressure deviation indicating alarm 5 connected in sequence, to monitor the temperature and pressure after the oxygen main shut-off valve 6 in real time to avoid safety accidents caused by over-temperature and over-pressure.

[0020] Further preferably, the pressure deviation relay 22 is connected to the SIS control system 1 to transmit the pressure difference data in the system to the SIS control system 1 to control the opening or closing of the oxygen main shut-off valve 6 and the nitrogen shut-off valve 7.

[0021] Preferably, the SIS control system 1 is connected to the nitrogen shut-off valve 7 via the first electromagnetic three-way valve 15, and the nitrogen shut-off valve 7 is connected to the second ball valve 13, so as to control the opening and closing of the high-pressure nitrogen in multiple steps.

[0022] Preferably, the pipeline between the oxygen main shut-off valve 6 and the oxygen main pipe 8 is connected to the first pressure signal transmitter 3 via the first ball valve 9, and the first pressure signal transmitter is respectively connected to the first pressure driver 10 and the first pressure indicating alarm 11 to monitor the pressure before the oxygen main shut-off valve 6 in real time.

[0023] Further preferably, the first pressure driver 10 is connected to the pressure deviation relay 22 via a system internal signal transmission line to detect the pressure difference before and after the oxygen main shut-off valve 6, so as to facilitate the SIS control system 1 to control the interlocking state of the oxygen main shut-off valve 6 and the nitrogen shut-off valve 7.

[0024] Example 2

[0025] When oxygen needs to be delivered to the gasifier for the first time, the SIS control system 1 generates a control signal to start delivering oxygen, which is transmitted to the oxygen main shut-off valve 6 through the second electromagnetic three-way valve 16, the third electromagnetic three-way valve 17, and the limit switch 2, and the oxygen main shut-off valve 6 is controlled to be opened to deliver high-purity oxygen to the oxygen main 8; when the second electromagnetic three-way valve 16, the third electromagnetic three-way valve 17, and the limit switch 2 are only kept in the open state, the valve opening feedback information and the limit switch 2 opening feedback information are respectively transmitted to the SIS control system 1, and the nitrogen shut-off valve 7 is controlled to be closed at this time. When the SIS control system 1 detects that the nitrogen shut-off valve 7 is closed, the oxygen main shut-off valve 6 is opened to deliver high-purity oxygen to the oxygen main 8 for reaction;

[0026] During the reaction, the first pressure signal transmitter 3, the first pressure driver 10 and the first pressure indicating alarm 11 are used to detect that the pressure before the oxygen main shut-off valve 6 is within the normal range; at the same time, the temperature detector 14, the temperature indicating alarm 18 and the temperature driver 19 are used to detect that the temperature after the oxygen main shut-off valve 6 is within the normal range, and the second pressure signal transmitter 4, the second pressure indicating alarm 20 and the pressure driver 21 are used to detect that the pressure after the oxygen main shut-off valve 6 is within the normal range.

[0027] When it is necessary to stop the oxygen delivery, close the second electromagnetic three-way valve 16, the third electromagnetic three-way valve 17, the limit switch 2, and the oxygen main shut-off valve 6. When the SIS control system 1 detects that the oxygen main shut-off valve 6 is in place and the limit switch 2 also transmits the information that it is in place, the nitrogen shut-off valve 7 can be opened at this time, and high-pressure nitrogen is delivered to the system. The high-pressure nitrogen is used to seal the oxygen in the oxygen main 8 to prevent it from escaping and causing safety accidents; and the detection device is used to detect the pressure and temperature before and after the oxygen main shut-off valve 6.

[0028] When it is necessary to switch from nitrogen to oxygen, gradually reduce the output of nitrogen, use the pressure deviation relay 22 and the pressure deviation indication alarm 5 to detect the pressure before and after the oxygen main shut-off valve 6. When the pressure difference before and after the oxygen main shut-off valve is ≥ 0.3MP A When the signal is transmitted to the SIS control system, the nitrogen shut-off valve 7 can be closed, the oxygen main shut-off valve 6 can be opened, and high-purity oxygen can be delivered to the oxygen main 8.

Claims

1. An oxygen main shut-off valve interlock system, characterized in that: The SIS control system (1) is connected to the oxygen main pipe cut-off valve (6) via the second electromagnetic three-way valve (16) and the third electromagnetic three-way valve (17) and the limit switch (2); the oxygen main pipe cut-off valve (6) is respectively connected to the oxygen main pipe (8) and the detection device; the SIS control system (1) is connected to the detection device via the nitrogen cut-off valve (7) and the check valve (12); the limit switch (2) and the pressure detection device are connected to the SIS control system (1).

2. An oxygen main shut-off valve interlock system according to claim 1, characterized in that: The detection device comprises a temperature monitoring device and a pressure detection device; the temperature monitoring device comprises a temperature detector (14), a temperature indicating alarm (18) and a temperature driver (19) which are connected in sequence; the pressure detection device comprises a second pressure signal transmitter (4), a second pressure indicating alarm (20), a pressure driver (21), a pressure deviation relay (22) and a pressure deviation indicating alarm (5) which are connected in sequence.

3. An oxygen main shut-off valve interlock system according to claim 2, characterized in that: The pressure deviation relay (22) is connected to the SIS control system (1).

4. An oxygen main shut-off valve interlock system according to claim 1, characterized in that: The SIS control system (1) is connected to the nitrogen shut-off valve (7) via a first electromagnetic three-way valve (15), and the nitrogen shut-off valve (7) is connected to the second ball valve (13).

5. The oxygen main shut-off valve interlock system according to claim 1, characterized in that: The pipeline between the oxygen main shut-off valve (6) and the oxygen main pipe (8) is connected to the first pressure signal transmitter (3) via the first ball valve (9), and the first pressure signal transmitter is respectively connected to the first pressure driver (10) and the first pressure indicating alarm (11).

6. An oxygen main shut-off valve interlock system according to claim 5, characterized in that: The first pressure driver (10) is connected to the pressure deviation relay (22) via a signal transmission line inside the system.

Images