Abstract: The determination of large-scale coal chemical industry flare system mainly includes two aspects: the determination of the number of flare discharge systems and the determination of flare emissions. At present, the high-pressure hydrogen-rich torch discharge gas is blocked, pipelines and equipment are blocked, the small flow of the torch system is channeled to each other, and the high-altitude igniter is frequently activated during the operation of the torch. It is necessary to adopt targeted countermeasures to improve the operation effect of the flare system and ensure the better operation and function of large-scale coal chemical industry.
The coal chemical production equipment is complex, and the production equipment is showing a trend of large-scale production. Therefore, the composition of the flare gas in the production device is complicated, and the treatment is relatively difficult. How to take corresponding measures based on the actual situation, reasonably determine the coal chemical flare system, and properly handle the problems existing in the flare operation, and improve the reliability and stability of the system operation, this is not to be ignored.1 Determination of large-scale coal chemical flare systemDuring the operation of the coal chemical industry flare system, in order to improve the overall performance and operating efficiency of the system, the following two aspects should be reasonably determined.1.1 Determination of the number of flare exhaust systemsThe process system of coal chemical industry is complex and takes a long time. It often goes through coal gasification, purification, methanol and olefin production, olefin separation, polypropylene, polyethylene and other devices. During the production process, due to the complexity of the process and the high requirements on the comprehensive skills of the operators, there may be varying degrees of leakage or emissions in accident conditions. In addition, due to the complex composition of coal, after different processes are processed, the exhaust gas composition is complex. In order to ensure the effective operation of the flare system, the treated gas must maintain sufficient heating value to meet the combustion needs, and the general heating value is 7 880kJ/Nm3 to meet the requirements. After inspection, if the calorific value is unqualified, it needs to be mixed with a burning medium to smoothly discharge the gas and achieve the goal of complete combustion. In determining the number of flare exhaust systems, it is necessary to consider the safety and stability of the system, while also ensuring that the calorific value can maintain its normal combustion needs. And consider the discharge medium, discharge gas temperature, pressure, cost, etc., and reasonably determine the number of flare discharge systems. This will ensure the normal and stable operation of the system and make it more effective.1.2 Determination of flare emissionWhen determining the amount of torch discharge, in order to improve work efficiency and ensure that the requirements are met, it is necessary to consider the start and shutdown of process equipment, fire accidents, water and power outages, steam, emergencies, etc. If the same accident causes emissions from the entire plant or device, the discharge flow-time curve of each device should be superimposed when determining, and the maximum value should be taken. If there is no flow-time curve, confirm it according to experience, formula and design specifications2 Problems in the operation of large coal chemical torchesAlthough the operation of the coal chemical industry flare system plays an important role and has also received attention and attention, there are problems in the operation of the flare system at present.2.1 The exhaust gas of the high-pressure hydrogen-rich flare is blockedWhen the high-pressure hydrogen-rich torch is discharged, the pressure will increase, which will also be hindered to some extent. During start-up and furnace cutting, the exhaust gas contains a large amount of condensate, which causes the liquid level of the water seal valve to rise and exceed the specified value. When cutting the furnace, the cut-out and cut-in gases are mixed, and after the heat exchange, the large temperature difference is added, and the steam is condensed. The application of long-distance exposed pipelines lacks insulation measures, which causes a large amount of heat to be lost. The presence of non-condensable gases will also reduce the freezing point of water vapor. After the standby furnace is heated up and the load increases, as the synthesis gas is introduced, the low temperature and high temperature gas will merge, and finally a large amount of condensate will exist.2.2 Blockage of pipelines and equipmentThe blockage of the pipeline and equipment of the high-pressure hydrogen-rich flare system will also affect the operation of the entire system. The gas discharged by the high-pressure hydrogen-rich torch contains a lot of coal ash. If it is not removed in time and effectively, the coal ash will be deposited in the pipe network, which will cause blockage, prolong the drainage time, block the level gauge, and even fail to close the valve after it is opened. , And ultimately affect the operation of the torch system.2.3 The small flow of the torch system crosses each otherThe phenomenon of each small flow of torch gas channeling each other. Each small flow gas shares a safety water seal system, the discharge time of the discharge gas is different, and the discharge pressure varies greatly. It causes the torch gas to rush to each other, causing the pressure to rise, and black smoke is emitted when the torch is burning.2.4 Frequent actions of high-altitude igniterThe remote ignition system of the torch system operates frequently and is affected by the high-altitude wind direction, which causes a large deviation in the temperature of the detection point, and the system even has a false alarm. In the end, frequent high-altitude ignition operations not only reduce the service life of the igniter, but also restrict its effective performance.3 Countermeasure analysis of large-scale coal chemical torch operation problemsIn order to deal with the shortcomings in the operation of the torch and improve the operation effect of the coal chemical industry, it is necessary to adopt the following strategies.3.1 Countermeasures for obstructed discharge gas from high-pressure hydrogen-rich flareImprove the setting of the flare gas pipeline, and reasonably set the insulation on the outside of the bare pipe to minimize heat loss. In winter, special staff will be arranged to patrol and inspect, and carry out heat tracing and insulation protection work. Use high-temperature resistant centrifugal pumps, add liquid separation tanks along the flare gas line, and pump the condensate to the sewage device for treatment.3.2 Countermeasures for blockage of pipelines and equipmentSeparate tanks are added at the discharge end and the middle of the long-distance pipeline to separate the liquid normally. Reasonably arrange staff to strengthen management and inspections, pay attention to maintenance and management, and learn more about pipeline and equipment blockage problems. For possible deficiencies, immediate repair measures must be taken to eliminate possible accidents in the bud. Strengthen the maintenance and management of pipelines and level gauges, and use nitrogen and water as the back-purge medium to ensure the normal operation of pipelines and equipment and achieve effective prevention of clogging.3.3 Countermeasures for the mutual channeling of each small flow torch systemIn order to deal with the problem of black smoke from the small flow torch, it is necessary to appropriately increase the auxiliary fan to increase the air volume, ensure sufficient air, and effectively assist the combustion to avoid black smoke. For small flow torches, separate small flow torches, high pressure and small flow torches use safety water seals, and low and ultra low pressure torches are newly equipped with flame arresters to ensure normal combustion and avoid mutual chasing.3.4 Countermeasures for frequent actions of high-altitude ignitersImprove equipment design, add detectors to the torch head, commonly used infrared detectors or ultraviolet detectors, and play an important role to assist in the judgment and analysis of signals. Reasonably set the ignition interlock logic of the torch system, that is, when the temperature of a detection point is 2 000 ℃, the system judges that the torch is burning normally to avoid system false alarms.4 ConclusionThe determination of the torch system is a very critical process in the coal chemical industry, and the degree of attention should be increased, and the relevant parameters should be determined reasonably to ensure the stable and reliable operation of the system. We should recognize the existing shortcomings and take targeted measures to ensure the normal and stable operation of the torch, and promote the better functioning of large-scale coal chemical industries.
Post time: 21-09-21