DCS torch system control method and DCS torch control system

Abstract

The embodiment of the invention relates to the technical field of ground torches, and discloses a DCS torch system control method and a DCS torch control system.The method comprises the steps that a video monitoring device is used for monitoring torch combustion states in a six-stage main torch subsystem, a low-pressure torch subsystem and an alkaline tower tail gas torch subsystem; the DCS control device conducts interlocking adjustment on gas valves and incandescent lights in the six-stage main torch subsystems according to the gas pressure, the temperature and the torch combustion state. The DCS control device conducts interlocking adjustment on a gas valve and an incandescent light in the low-pressure torch subsystem according to the gas pressure, the temperature and the torch combustion state. The DCS control device carries out interlocking adjustment on a gas valve and an incandescent light in the tail gas torch subsystem of the alkaline washing tower according to the gas pressure, the temperature and the torch combustion state. By means of the technical scheme, the problems that in the prior art, a torch system is poor in operability, and much inconvenience is brought to operators can be effectively solved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of ground flare, and in particular to a DCS flare system control method and a DCS flare control system. Background Art

[0002] The flare system is a special combustion facility used to treat flammable and combustible toxic gases and steam that cannot be recovered and reprocessed in petrochemical plants, refineries, chemical plants and other plants or devices. It is an important measure to ensure safe production in factories and reduce environmental pollution. The ground flare system can ensure that the gas can be vented and burned in a timely, safe and reliable manner when it needs to be discharged, and ensure low-noise and smokeless combustion during operation. The ground flare system is mainly composed of a control valve, a ground flare (consisting of a burner group, a radiation-proof heat insulation cover and a protective wall), and a ground flare automatic ignition system; the gas venting combustion flame can be completely controlled within the radiation-proof heat insulation cover, and the flame cannot be seen by the outside world, minimizing the impact of heat radiation and noise on workers and surrounding equipment.

[0003] In the prior art, the ground flare system generally uses a set of PLC control systems to control the process and manage its operation. The main control scope includes the safety interlock, control and adjustment of the ground flare system. That is, the signals of the flare field instruments all enter the PLC system, and the PLC monitors the operating status of the flare system and makes necessary manual intervention. The PLC control system has certain defects, such as the poor visibility and operability of the PLC panel, which brings many inconveniences to the operators; and in an emergency, due to safety reasons, personnel cannot enter the flare area, which further increases the difficulty of problem handling and may pose a threat to safe production. Therefore, a safer, more reliable and efficient solution is urgently needed to ensure the safe and stable operation of the ground flare system. Summary of the invention

[0004] In view of the above problems, the present invention provides a DCS flare system control method and a DCS flare control system, which migrate the control system of the flare unit to a central distributed control system (DCS) to achieve remote monitoring and operation, which not only helps to improve work efficiency, but also prevents personnel from entering dangerous areas, thereby ensuring the personal safety and production safety of employees; and effectively solves the problems existing in the prior art that the flare system has poor operability and brings many inconveniences to operators.

[0005] In a first aspect, the present invention provides a DCS flare system control method, the method comprising: The video monitoring device is used to monitor the flare combustion status in the six-level main flare subsystem, the low-pressure flare subsystem and the caustic scrubber tail gas flare subsystem; The DCS control device interlocks and adjusts the gas valves and pilot lights in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion status; The DCS control device interlocks and adjusts the gas valve and pilot light in the low-pressure flare subsystem according to the gas pressure, temperature and flare combustion status; The DCS control device interlocks and adjusts the gas valve and the pilot light in the tail gas flare subsystem of the caustic washing tower according to the gas pressure, temperature and flare combustion status.

[0006] In an optional manner, the DCS control device interlocks and adjusts the gas valve and the pilot light in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion state, including: The DCS control device interlocks and adjusts the gas valves in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion status; The DCS control device interlocks and adjusts the pilot light in the six-level main flare subsystem according to the gas pressure, temperature and flare burning status.

[0007] In an optional manner, the DCS control device interlocks and adjusts the gas valves in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion state, including: When the main flare gas discharge pressure reaches the preset value of each level of discharge valve, the corresponding discharge valves are interlocked and controlled respectively; When the main flare gas pressure reaches the preset value of each level of steam smoke suppression regulating valve, the corresponding steam smoke suppression regulating valves are interlocked and controlled respectively, and adjusted according to the flare combustion status at the same time; When the main flare gas pressure reaches the preset value of each level of nitrogen purge valve, the corresponding nitrogen purge valves are interlocked and controlled respectively.

[0008] In an optional manner, when the main flare gas discharge pressure value reaches the preset value of each level of discharge valve, the step of interlocking and controlling the corresponding discharge valves respectively includes: When the main flare gas discharge pressure reaches the preset value, the discharge valves at each level are interlocked and opened respectively; When the main flare gas discharge pressure drops to 5KPa -6KPa, the first and second level discharge valves are interlocked and closed respectively; When the main flare gas discharge pressure drops to 4.5KPa -5KPa, the third and fourth level discharge valves are interlocked and closed respectively; When the main flare gas discharge pressure value drops to 4KPa-4.5KPa, the fifth and sixth level discharge valves are interlocked and closed respectively.

[0009] In an optional manner, when the flare gas pressure value reaches the preset value of each level of steam smoke suppression regulating valve, the corresponding steam smoke suppression regulating valves are interlocked and controlled respectively, and the adjustment step is performed according to the flare combustion state, including: When the main flare gas pressure reaches 3KPa, the interlock opens 25% of the first and second level steam smoke suppression regulating valves, and adjusts according to the flare combustion status; When the main flare gas pressure reaches 21KPa, the interlock opens the 25% third and fourth level steam smoke suppression regulating valves and adjusts them according to the flare combustion status; When the main flare gas pressure reaches 23KPa, the interlock opens 25% of the fifth and sixth level steam smoke suppression switch valves and adjusts them according to the flare combustion status.

[0010] In an optional manner, when the main flare gas pressure value reaches the preset value of each level of nitrogen purge valve, the step of interlocking and controlling the corresponding nitrogen purge valves respectively includes: When the main flare gas pressure drops to 7KPa-8KPa, the first and second level nitrogen purge valves are interlocked and opened respectively; When the main flare gas pressure drops to 6KPa-7KPa, the third and fourth level nitrogen purge valves are interlocked and opened respectively; When the main flare gas pressure drops to 5KPa-6KPa, the fifth and sixth stage nitrogen purge valves are interlocked and opened respectively.

[0011] In an optional manner, the DCS control device interlocks and adjusts the pilot light in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion state, including: The temperature transmitter is used to monitor the temperature of the pilot lamp in the six-stage main flare subsystem; When the temperature of the pilot lamp is lower than the preset temperature value, the DCS control device interlocks the igniter in the six-level main torch subsystem to automatically ignite and light the pilot lamp.

[0012] In an optional manner, the DCS control device interlocks and adjusts the gas valve and the pilot light in the low-pressure flare subsystem according to the gas pressure, temperature and flare combustion state, including: When the low-pressure flare gas pressure is lower than the preset threshold or the low-pressure flare gas pipe flame arrester temperature is higher than the preset threshold, the interlock opens the nitrogen purge valve; The low-pressure flare steam smoke suppression switch valve is normally open 1 / 4 and adjusted according to the flare combustion status; The temperature of the pilot lamp in the low-pressure flare subsystem is monitored using a temperature transmitter; When the temperature of the pilot lamp is lower than the preset temperature value, the DCS control device interlocks the igniter in the low-pressure torch subsystem to automatically ignite and light the pilot lamp.

[0013] In an optional manner, the DCS control device interlocks and adjusts the gas valve and the pilot light in the tail gas flare subsystem of the caustic washing tower according to the gas pressure, temperature and flare combustion state, including: When the tail gas pressure of the alkali washing tower is lower than the preset threshold or the flame arrester temperature of the tail gas pipe of the alkali washing tower is higher than the preset threshold, the nitrogen purge valve is interlocked to open; The steam smoke elimination switch valve of the tail gas of the alkali washing tower is normally opened 1 / 4 and adjusted according to the burning state of the torch; The temperature transmitter is used to monitor the temperature of the pilot lamp in the tail gas flare subsystem of the caustic scrubber. When the temperature of the pilot lamp is lower than the preset temperature value, the DCS control device interlocks the igniter in the tail gas flare subsystem of the caustic washing tower to automatically ignite and light the pilot lamp.

[0014] In an optional manner, the method further comprises the following steps: The DCS control device interlocks and controls the liquid level switch valves of the flare gas water seal tanks in each flare subsystem according to the liquid level; The DCS control device interlocks and controls the nitrogen purge valves of each flare subsystem according to the flare gas water seal tank pressure; The DCS control device performs interlocking control on the condensate pumps in each flare subsystem; The DCS control device uses the combustible gas alarm connected to it to alarm the combustible gas and toxic gas in each flare subsystem.

[0015] In an optional manner, the DCS control device performs interlock control on the liquid level switch valve of the flare gas water seal tank in each flare subsystem according to the liquid level of the flare gas water seal tank. When the liquid level of the flare gas water seal tank is ≤550mm, the interlock opens the liquid level switch valve; When the liquid level of the flare gas water seal tank is greater than 580mm, the interlock closes the liquid level switch valve.

[0016] In an optional manner, the DCS control device performs interlock control on the nitrogen purge valve of each flare subsystem according to the pressure of the flare gas water seal tank in each flare subsystem. When the flare gas water seal tank pressure is lower than the preset threshold, the interlock opens the nitrogen purge valve; When the flare gas water seal tank pressure is higher than the preset threshold, the interlock closes the nitrogen purge valve.

[0017] In a second aspect, the present invention further provides a DCS flare control system, comprising: The low-pressure flare subsystem, alkali scrubber tail gas flare subsystem and six-stage main flare subsystem are arranged in sequence; Video monitoring devices for monitoring the flare combustion status in the six-stage main flare subsystem, low-pressure flare subsystem and caustic scrubber tail gas flare subsystem; Temperature transmitters for monitoring the temperatures of the six-stage main flare subsystem, low-pressure flare subsystem and caustic scrubber tail gas flare subsystem; Pressure transmitters for monitoring the gas pressure of the six-stage main flare subsystem, low-pressure flare subsystem and caustic wash tower tail gas flare subsystem; A combustible gas alarm that alarms the combustible gas and toxic gas in each flare subsystem respectively; And a DCS control device which is respectively connected to the video monitoring device, temperature transmitter, pressure transmitter and combustible gas alarm and performs interlocking control on the six-level main flare subsystem, low-pressure flare subsystem and alkali washing tower tail gas flare subsystem.

[0018] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings: Figure 1 A schematic flow chart of a first embodiment of a DCS flare system control method provided by the present invention is shown; Figure 2 A schematic flow chart of a first embodiment of a DCS flare system control method provided by the present invention is shown; Figure 3 A schematic flow chart of a first embodiment of a DCS flare system control method provided by the present invention is shown; Figure 4 A schematic flow chart of a first embodiment of a DCS flare system control method provided by the present invention is shown; Figure 5 A schematic flow chart of a first embodiment of a DCS flare system control method provided by the present invention is shown; Figure 6 A schematic flow chart of a first embodiment of a DCS flare system control method provided by the present invention is shown; Figure 7 A schematic flow chart of a second embodiment of a DCS flare system control method provided by the present invention is shown; Figure 8 A schematic structural diagram of an embodiment of a DCS flare control system provided by the present invention is shown. DETAILED DESCRIPTION

[0020] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0021] Figure 1 FIG. 1 is a flow chart showing a first embodiment of a DCS flare system control method of the present invention, which is executed by a DCS flare control system. Figure 1 As shown, the method comprises the following steps: S100. Use video monitoring devices to monitor the flare combustion status in the six-level main flare subsystem, the low-pressure flare subsystem and the caustic washing tower tail gas flare subsystem respectively; preferably, the video monitoring device is a monitoring camera, which can continuously monitor the operation status of the flare online, and the signal is led to the TV monitor in the central control room to timely observe the combustion status of the flare and the smoke suppression effect, judge the combustion status of the flare according to the color of the flame, and manually adjust the steam smoke suppression amount.

[0022] S200 and DCS control devices interlock and adjust the gas valves and pilot lights in the six-stage main flare subsystem according to gas pressure, temperature and flare combustion status; S300 and DCS control devices interlock and adjust the gas valve and pilot light in the low-pressure flare subsystem according to gas pressure, temperature and flare combustion status; The S400 and DCS control devices interlock and adjust the gas valve and the pilot light in the tail gas flare subsystem of the caustic washing tower according to the gas pressure, temperature and flare combustion status.

[0023] Furthermore, if Figure 2 As shown, the S200 and DCS control devices interlock and adjust the gas valves and the pilot lights in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion state, including the following steps: S210, DCS control device interlocks and adjusts the gas valves in the six-stage main flare subsystem according to gas pressure, temperature and flare combustion status; S220, DCS control device interlocks and adjusts the pilot light in the six-level main flare subsystem according to the gas pressure, temperature and flare burning status.

[0024] Furthermore, if Figure 3 As shown, S210, the DCS control device interlocks and adjusts the gas valve in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion state, including the following steps: S211, when the main flare gas discharge pressure value reaches the preset value of each level of discharge valve, the corresponding discharge valves are interlocked and controlled respectively; S212, when the main flare gas pressure reaches the preset value of each level of steam smoke suppression regulating valve, the corresponding steam smoke suppression regulating valves are interlocked and controlled respectively, and adjusted according to the flare combustion state; S213. When the main flare gas pressure reaches the preset value of each level of nitrogen purge valve, the corresponding nitrogen purge valves are interlocked and controlled respectively.

[0025] In some embodiments, S211, when the main flare gas discharge pressure value reaches the preset value of each level of discharge valve, the corresponding discharge valve steps are interlocked and controlled respectively, including: When the main flare gas discharge pressure reaches the preset value, the discharge valves at each level are interlocked and opened respectively; for example: the preset value of the main flare gas discharge pressure is 3KPa, then when the main flare gas discharge pressure reaches 3KPa, the discharge valves at each level are interlocked and opened respectively.

[0026] When the main flare gas discharge pressure drops to 5KPa -6KPa, the first and second level discharge valves are interlocked and closed respectively; When the main flare gas discharge pressure drops to 4.5KPa -5KPa, the third and fourth level discharge valves are interlocked and closed respectively; When the main flare gas discharge pressure value drops to 4KPa-4.5KPa, the fifth and sixth level discharge valves are interlocked and closed respectively.

[0027] In some embodiments, S212, when the flare gas pressure value reaches the preset value of each level of steam smoke suppression regulating valve, the corresponding steam smoke suppression regulating valves are interlocked and controlled respectively, and the adjustment step is performed according to the flare combustion state, including: When the main flare gas pressure reaches 3KPa, the interlock opens 25% of the first and second level steam smoke suppression regulating valves, and adjusts according to the flare combustion status; When the main flare gas pressure reaches 21KPa, the interlock opens the 25% third and fourth level steam smoke suppression regulating valves and adjusts them according to the flare combustion status; When the main flare gas pressure reaches 23KPa, the interlock opens 25% of the fifth and sixth level steam smoke suppression switch valves and adjusts them according to the flare combustion status.

[0028] In some embodiments, S213, when the main flare gas pressure value reaches the preset value of each level of nitrogen purge valve, the corresponding nitrogen purge valve steps are interlocked and controlled respectively, including: When the main flare gas pressure drops to 7KPa-8KPa, interlock and open the first and second level nitrogen purge valves respectively; When the main flare gas pressure drops to 6KPa-7KPa, the third and fourth level nitrogen purge valves are interlocked and opened respectively; When the main flare gas pressure drops to 5KPa-6KPa, the fifth and sixth stage nitrogen purge valves are interlocked and opened respectively.

[0029] Furthermore, if Figure 4 As shown, the steps of interlocking and adjusting the pilot light in the six-stage main flare subsystem according to the gas pressure, temperature and flare burning state of S220 and DCS control device include: S221. Use a temperature transmitter to monitor the temperature of the pilot lamp in the six-stage main flare subsystem; S222. When the temperature of the pilot lamp is lower than the preset temperature value, the DCS control device interlocks the igniter in the six-level main torch subsystem to automatically ignite and light the pilot lamp.

[0030] For example: when the temperature of the pilot lamp is lower than 150℃, the DCS control device interlocks the igniter in the six-level main flare subsystem to automatically ignite and light the pilot lamp. The igniter can be operated locally, automatically by DCS, or manually, thus ensuring the safe operation of the flare system.

[0031] Furthermore, if Figure 5 As shown, the S300 and DCS control devices interlock and adjust the gas valve and the pilot light in the low-pressure flare subsystem according to the gas pressure, temperature and flare combustion state, including: S310. When the low-pressure flare gas pressure is lower than the preset threshold or the temperature of the low-pressure flare gas pipe flame arrester is higher than the preset threshold, the interlock opens the nitrogen purge valve; for example: when the low-pressure flare gas pressure is lower than 0.5 KPa or the temperature of the low-pressure flare gas pipe flame arrester is higher than 85°C, the interlock opens the nitrogen purge valve.

[0032] S320, low-pressure flare steam smoke suppression switch valve is normally open 1 / 4, and is adjusted according to the flare combustion status; S330, using a temperature transmitter to monitor the temperature of the pilot lamp in the low-pressure flare subsystem; S340: When the temperature of the pilot lamp is lower than the preset temperature value (preset 150°C), the DCS control device interlocks the igniter in the low-pressure torch subsystem to automatically ignite and light the pilot lamp.

[0033] Furthermore, if Figure 6 As shown, the S400 and DCS control devices interlock and adjust the gas valve and the pilot light in the tail gas flare subsystem of the caustic washing tower according to the gas pressure, temperature and flare combustion state, including: S410, when the tail gas pressure of the alkali washing tower is lower than the preset threshold or the temperature of the flame arrester of the tail gas pipe of the alkali washing tower is higher than the preset threshold, the interlock opens the nitrogen purge valve; for example: when the tail gas pressure of the alkali washing tower is lower than 0.1KPa or the temperature of the flame arrester of the tail gas pipe of the alkali washing tower is higher than 85℃, the interlock opens the nitrogen purge valve.

[0034] S420, the alkali scrubber tail gas steam smoke elimination switch valve is normally opened 1 / 4, and adjusted according to the flare combustion status; S430, using a temperature transmitter to monitor the temperature of the pilot lamp in the tail gas flare subsystem of the caustic washing tower; S440: When the temperature of the pilot lamp is lower than the preset temperature value (preset 150°C), the DCS control device interlocks the igniter in the tail gas flare subsystem of the caustic washing tower to automatically ignite and light the pilot lamp.

[0035] Figure 7 FIG. 2 is a flow chart showing a second embodiment of a DCS flare system control method of the present invention, which is executed by a DCS flare control system. Figure 7 As shown, the method comprises the following steps: S100, using a video monitoring device to monitor the flare combustion status in the six-level main flare subsystem, the low-pressure flare subsystem and the caustic washing tower tail gas flare subsystem; S200 and DCS control devices interlock and adjust the gas valves and pilot lights in the six-stage main flare subsystem according to gas pressure, temperature and flare combustion status; S300 and DCS control devices interlock and adjust the gas valve and pilot light in the low-pressure flare subsystem according to gas pressure, temperature and flare combustion status; S400 and DCS control devices interlock and adjust the gas valve and pilot light in the tail gas flare subsystem of the caustic washing tower according to the gas pressure, temperature and flare combustion status; S500 and DCS control devices interlock and control the liquid level switch valves of the flare gas and water seal tanks in each flare subsystem according to the liquid level; S600 and DCS control devices interlock and control the nitrogen purge valves of each flare subsystem according to the flare gas water seal tank pressure; S700 and DCS control devices perform interlocking control on the condensate pumps in each flare subsystem; The S800 and DCS control devices use the combustible gas alarms connected to them to alarm the combustible and toxic gases in each flare subsystem.

[0036] Furthermore, in the step of interlocking the liquid level switch valve of the flare gas water seal tank in each flare subsystem, S500 and the DCS control device perform interlocking control on the liquid level switch valve of the flare gas water seal tank in each flare subsystem. When the liquid level of the flare gas water seal tank is ≤550mm, the interlock opens the liquid level switch valve; When the liquid level of the flare gas water seal tank is greater than 580mm, the interlock closes the liquid level switch valve.

[0037] Furthermore, in the step of interlocking the nitrogen purge valve of each flare subsystem according to the flare gas water seal tank pressure of S600 and DCS control device, When the flare gas water seal tank pressure is lower than the preset threshold, the interlock opens the nitrogen purge valve; When the flare gas water seal tank pressure is higher than the preset threshold, the interlock closes the nitrogen purge valve.

[0038] For example: when the pressure of the flare gas water seal tank is lower than 0KPa, the interlock opens the nitrogen purge valve; when the pressure of the flare gas water seal tank is higher than 0.7KPa, the interlock closes the nitrogen purge valve.

[0039] Figure 8 The structure diagram of the DCS flare control system of the present invention is shown, which is used to execute the DCS flare system control method in the above embodiment. Figure 8 As shown, the DCS flare control system includes: A low-pressure flare subsystem 10, an alkali scrubber tail gas flare subsystem 20 and a six-stage main flare subsystem 30 are arranged in sequence; A video monitoring device 40 for monitoring the flare combustion status in the six-stage main flare subsystem 30, the low-pressure flare subsystem 10 and the caustic washing tower tail gas flare subsystem 20 respectively; A temperature transmitter 50 for monitoring the temperatures of the six-stage main flare subsystem 30, the low-pressure flare subsystem 10 and the caustic washing tower tail gas flare subsystem 20 respectively; A pressure transmitter 60 for monitoring the gas pressure of the six-stage main flare subsystem 30, the low-pressure flare subsystem 10 and the caustic washing tower tail gas flare subsystem 20 respectively; A combustible gas alarm 70 for respectively alarming combustible gas and toxic gas in each flare subsystem; And a DCS control device 80 which is respectively connected to the video monitoring device 40, the temperature transmitter 50, the pressure transmitter 60 and the combustible gas alarm 70, and performs interlocking control on the six-level main flare subsystem 30, the low-pressure flare subsystem 10 and the alkali washing tower tail gas flare subsystem 20.

[0040] In order to solve the above problems, the present invention improves the torch control system from the previous PLC control system to a DCS torch control system. The DCS torch control system is based on the basic design concept of decentralized control, centralized operation and management, and adopts a multi-level hierarchical, cooperative and autonomous structure. Its main features are its centralized management and decentralized control. The biggest feature of DCS in control is that it relies on the flexible configuration of various control and operation modules, and can realize diversified control strategies to meet the needs of different situations, making the proposition that is quite cumbersome and complex to implement in the unit combination instrument simple.

[0041] In addition, for locations within the flare boundary that do not meet the requirements of GBT50493-2019 "Petrochemical Combustible Gas and Toxic Gas Detection Alarm Design Standard", a new DCS flare control system is added, and a new signal is connected to the GDS system.

[0042] Preferably, the DCS flare control system of this embodiment is a supporting flare system for the 300,000-ton C5 separation device, the 50,000-ton C5 petroleum resin system, and the 100,000-ton C9 hydrogenation system. It adopts a multi-nozzle type, and the flare gas can obtain a sufficient combustion effect during normal and accidental discharges, thereby ensuring sufficient combustion during flare discharge. The low-pressure flare gas, alkali washing tower tail gas, and main flare gas all enter the closed ground flare combustion tower. The low-pressure flare gas and alkali washing tower tail gas are continuous discharge gases, which enter the supporting burners for combustion respectively; the main flare gas is divided into 6 levels to adopt pressure classification control; the whole set of ground flares can realize two ignition modes: automatic and on-site manual.

[0043] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system or other device. In addition, the embodiments of the present invention are not directed to any particular programming language.

[0044] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0045] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive.

[0046] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A DCS flare system control method, characterized in that: The method comprises: The video monitoring device is used to monitor the flare combustion status in the six-level main flare subsystem, the low-pressure flare subsystem and the caustic scrubber tail gas flare subsystem respectively; The DCS control device interlocks and adjusts the gas valves and pilot lights in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion status; The DCS control device interlocks and adjusts the gas valve and pilot light in the low-pressure flare subsystem according to the gas pressure, temperature and flare combustion status; The DCS control device interlocks and adjusts the gas valve and the pilot light in the tail gas flare subsystem of the caustic washing tower according to the gas pressure, temperature and flare combustion status.

2. The method according to claim 1, characterized in that The DCS control device interlocks and adjusts the gas valves and the pilot light in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion state, including: The DCS control device interlocks and adjusts the gas valves in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion status; The DCS control device interlocks and adjusts the pilot light in the six-level main flare subsystem according to the gas pressure, temperature and flare burning status.

3. The method according to claim 2, characterized in that The DCS control device interlocks and adjusts the gas valves in the six-stage main flare subsystem according to the gas pressure, temperature and flare combustion state, including: When the main flare gas discharge pressure reaches the preset value of each level of discharge valve, the corresponding discharge valves are interlocked and controlled respectively; When the main flare gas pressure reaches the preset value of each level of steam smoke suppression regulating valve, the corresponding steam smoke suppression regulating valves are interlocked and controlled respectively, and adjusted according to the flare combustion status at the same time; When the main flare gas pressure reaches the preset value of each level of nitrogen purge valve, the corresponding nitrogen purge valves are interlocked and controlled respectively.

4. The method according to claim 3, characterized in that: When the main flare gas discharge pressure value reaches the preset value of each level of discharge valve, the corresponding discharge valve steps are interlocked and controlled respectively, including: When the main flare gas discharge pressure reaches the preset value, the discharge valves at each level are interlocked and opened respectively; When the main flare gas discharge pressure drops to 5KPa -6KPa, the first and second level discharge valves are interlocked and closed respectively; When the main flare gas discharge pressure drops to 4.5KPa -5KPa, the third and fourth level discharge valves are interlocked and closed respectively; When the main flare gas discharge pressure value drops to 4KPa-4.5KPa, the fifth and sixth level discharge valves are interlocked and closed respectively.

5. The method according to claim 3, characterized in that: When the flare gas pressure reaches the preset value of each level of steam smoke suppression regulating valve, the corresponding steam smoke suppression regulating valve is interlocked and controlled respectively, and the adjustment step is performed according to the flare combustion state, including: When the main flare gas pressure reaches 3KPa, the interlock opens 25% of the first and second level steam smoke suppression regulating valves, and adjusts according to the flare combustion status; When the main flare gas pressure reaches 21KPa, the interlock opens the 25% third and fourth level steam smoke suppression regulating valves and adjusts them according to the flare combustion status; When the main flare gas pressure reaches 23KPa, the interlock opens 25% of the fifth and sixth level steam smoke suppression switch valves and adjusts them according to the flare combustion status.

6. The method according to claim 3, characterized in that When the main flare gas pressure value reaches the preset value of each level of nitrogen purge valve, the corresponding nitrogen purge valve steps are interlocked and controlled respectively, including: When the main flare gas pressure drops to 7KPa-8KPa, interlock and open the first and second level nitrogen purge valves respectively; When the main flare gas pressure drops to 6KPa-7KPa, the third and fourth level nitrogen purge valves are interlocked and opened respectively; When the main flare gas pressure drops to 5KPa-6KPa, the fifth and sixth level nitrogen purge valves are interlocked and opened respectively.

7. The method according to claim 2, characterized in that The DCS control device interlocks and adjusts the pilot light in the six-level main flare subsystem according to the gas pressure, temperature and flare combustion state, including: The temperature transmitter is used to monitor the temperature of the pilot lamp in the six-stage main flare subsystem; When the temperature of the pilot lamp is lower than the preset temperature value, the DCS control device interlocks the igniter in the six-level main torch subsystem to automatically ignite and light the pilot lamp.

8. The method according to claim 1, characterized in that: The DCS control device interlocks and adjusts the gas valve and the pilot light in the low-pressure flare subsystem according to the gas pressure, temperature and flare combustion state, including: When the low-pressure flare gas pressure is lower than the preset threshold or the low-pressure flare gas pipe flame arrester temperature is higher than the preset threshold, the interlock opens the nitrogen purge valve; The low-pressure flare steam smoke suppression switch valve is normally open 1 / 4 and adjusted according to the flare combustion status; The temperature of the pilot lamp in the low-pressure flare subsystem is monitored using a temperature transmitter; When the temperature of the pilot lamp is lower than the preset temperature value, the DCS control device interlocks the igniter in the low-pressure torch subsystem to automatically ignite and light the pilot lamp.

9. The method according to claim 1, characterized in that: The DCS control device interlocks and adjusts the gas valve and the pilot light in the tail gas flare subsystem of the caustic washing tower according to the gas pressure, temperature and flare combustion state, including: When the tail gas pressure of the alkali washing tower is lower than the preset threshold or the flame arrester temperature of the tail gas pipe of the alkali washing tower is higher than the preset threshold, the nitrogen purge valve is interlocked to open; The steam smoke elimination switch valve of the tail gas of the alkali washing tower is normally opened 1 / 4 and adjusted according to the burning state of the torch; The temperature transmitter is used to monitor the temperature of the pilot lamp in the tail gas flare subsystem of the caustic scrubber. When the temperature of the pilot lamp is lower than the preset temperature value, the DCS control device interlocks the igniter in the tail gas flare subsystem of the caustic washing tower to automatically ignite and light the pilot lamp.

10. The method according to claim 1, characterized in that The method further comprises the following steps: The DCS control device interlocks and controls the liquid level switch valves of the flare gas water seal tanks in each flare subsystem according to the liquid level; The DCS control device interlocks and controls the nitrogen purge valves of each flare subsystem according to the flare gas water seal tank pressure; The DCS control device performs interlocking control on the condensate pumps in each flare subsystem; The DCS control device uses the combustible gas alarm connected to it to alarm the combustible gas and toxic gas in each flare subsystem.

11. The method according to claim 10, characterized in that The DCS control device interlocks the liquid level switch valve according to the liquid level of the flare gas water seal tank in each flare subsystem. When the liquid level of the flare gas water seal tank is ≤550mm, the interlock opens the liquid level switch valve; When the liquid level of the flare gas water seal tank is greater than 580mm, the interlock closes the liquid level switch valve.

12. The method according to claim 10, characterized in that The DCS control device interlocks the nitrogen purge valve according to the flare gas water seal tank pressure in each flare subsystem. When the flare gas water seal tank pressure is lower than the preset threshold, the interlock opens the nitrogen purge valve; When the flare gas water seal tank pressure is higher than the preset threshold, the interlock closes the nitrogen purge valve.

13. A DCS torch control system, characterized in that: include: The low-pressure flare subsystem, alkali scrubber tail gas flare subsystem and six-stage main flare subsystem are arranged in sequence; Video monitoring devices for monitoring the flare combustion status in the six-stage main flare subsystem, low-pressure flare subsystem and caustic scrubber tail gas flare subsystem; Temperature transmitters for monitoring the temperatures of the six-stage main flare subsystem, low-pressure flare subsystem and caustic scrubber tail gas flare subsystem; Pressure transmitters for monitoring the gas pressure of the six-stage main flare subsystem, low-pressure flare subsystem and caustic wash tower tail gas flare subsystem; A combustible gas alarm that alarms the combustible gas and toxic gas in each flare subsystem respectively; And a DCS control device which is respectively connected to the video monitoring device, temperature transmitter, pressure transmitter and combustible gas alarm and performs interlocking control on the six-level main flare subsystem, low-pressure flare subsystem and alkali washing tower tail gas flare subsystem.

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