SC-1型气相裂解炉运行中的问题及对策

Problems and countermeasures of SC-1 gas phase cracking furnace unit during operation

针对中国石油兰州石化公司SC-1型气相裂解炉在运行过程中出现的炉管堵塞、投油过程中CO快速上升以及运行周期短等问题,从工艺等方面进行了分析,并提出相应对策。结果表明:气相裂解炉在70%低负荷运行时,将2个通道的稀释比从0.45分别提至0.50,0.55,保证原料流量和稀释蒸汽流量之和大于6 300 kg/h,横跨压力平均在334 kPa,提高14 kPa,解决了气相裂解炉炉管堵塞的问题;气相裂解炉投油期间,通过改变投油方式和缩短投油时间,裂解气中CO质量浓度上升至865 mg/L,较之前下降185 mg/L,持续时间从25 min缩短至10 min,降低了对碳二加氢反应器的影响;将结焦抑制剂二甲基二硫更换为NS-17 A 6乙烯抗焦活性剂后,裂解炉运行周期延长了10 d,炉管表面温度大幅下降,且保持一定的裂解深度。

Aiming at the problems such as the pipe blockage,the rapid increase of CO during oil injection and the short operating period in the process of running the SC-1 gas-phase cracking furnace of Lanzhou Petrochemical Company,PetroChina,the process was analyzed and put forward the corresponding countermeasures.The results showed that the gas phase cracking furnace tube blockage could be solved by increasing the dilution ratio of the two channels from 0.45 to 0.50 and 0.55 to ensure the sum of the raw material flow and the diluted steam flow was greater than 6 300 kg/h and rising the average spanning pressure 14 kPa higher to reach 334 kPa when the furnace is at 70%low load operation.During the oil injection period of the gas phase cracking furnace,CO rose to 865 mg/L in the cracking gas by changing the oil injection method and shortening the oil injection time,which decreased by 185 mg/L from the previous time,and the duration was shortened from 25 min to 10 min.The effect on carbon dihydrogenation reactor was reduced.After replacing the coking inhibitor dimethyl disulfide with NS-17 A 6 ethylene anti-coke active agent,the operating cycle of the cracking furnace was extended by 10 d,and the surface temperature of the furnace tube dropped significantly,and a certain cracking depth was maintained.