冷箱出口温度过低的原因分析与处理

CAUSE ANALYSIS AND TREATMENT OF THE OVER-LOW TEMPERATURE AT THE OUTLET OF COLD BOX IN ETHYLENE PLANT

针对近年来大型乙烯装置开工过程中出现的冷箱出口温度过低的问题,采集了乙烯装置冷箱出口氢气、高压尾气、低压氢气/甲烷、低压尾气、甲烷循环气的温度统计数据。通过分析,得出导致冷箱出口温度降低的原因是丙烯热剂侧、甲烷循环气侧形成了水合物,导致冷箱的换热效率降低,出现物料温度降低的现象。经采用注丙醇、吹热氮等工艺措施,使冷箱系统的温度恢复正常。

To solve the over-low temperature problem at the outlet of cold box during the startup of large-scale ethylene plant in recent years,temperature statistics of hydrogen at the outlet of cold box,HP offgas,LP hydrogen / methane,LP offgas and recycle methane were collected and analyzed,and the results showed that the hydrates formed in the cold box led to lower heat exchange efficiency of the cold box and lower temperature of the material. Some measures including propanol injection and hot nitrogen blowing were taken to bring the temperature in cold box system back to normal.