制氢转化炉转化管爆管原因分析

Analysis of causes of tube explosion in the conversion furnace of hydrogen generation unit

制氢转化炉炉管的爆管部位一般集中在高温区,中国兵器北方华锦化学工业集团炼化分公司制氢转化炉爆管区域发生在低温区,设计使用寿命10万小时,实际使用4万5千多小时。采用宏观、微观、化学成分及力学性能分析等手段,对转化炉管材质劣化现象进行了综合分析,分析认为:高温预热器堵塞且火焰过长,高负荷运行时烟气流通不畅,火焰发飘舔炉管,造成炉管超温,长时间运行会发生高温蠕变;热膨胀不均匀,局部应力过大,导致爆管,并提出几点建议。

The tube explosion normally occurs in the high-temperature zone of reforming furnace of hydrogen generation unit.Whereas,the tube explosion has occurred in the low-temperature zone of the reforming furnace of hydrogen generation unit in Huajin Refining&Chemical Co.of China North Industry Group.The design life is 100,000 hours,but the actual operating life is about 45,000 hours.The metallurgy deterioration of the furnace is analyzed with micro,macro,chemical composition and mechanics testing methods.It is concluded from analysis that the culprits are that the high temperature pre-heater is blocked and the flame is too long,the flue gas flow is not smooth during the high operating load,the flame is floating,and the furnace tubes are lipped which causes the furnace tube to be extremely hot and high temperature creep will occur if it runs for a long time;In addition,the other causes are that the thermal expansion is not uniform,and the local stress is too high,which results in tubes’explosion.Several recommendations are presented.