苯加氢装置换热系统的改造

Modification of heat exchanger of benzene hydrogenation unit

介绍了苯加氢生产环己烷的工艺流程,根据苯加氢反应的特点,分析了苯加氢装置中换热系统的物料走向和热量交换。针对原设计中温度为130℃的环己烷热量未得到利用,降温时消耗冷却水的问题,提出了增加苯预热器的改造措施。改造后,利用130℃的环己烷对原料苯预热,使苯的进料温度由原来的40℃提高到120℃,加氢反应放热量增加,装置副产蒸汽的量提高0.5t/h,冷却水用量减少8.76t/h,取得了一定的经济效益。改造后的装置运行平稳,生产周期延长,达到了节能降耗的目的。

The technical process of producing cyclohexane by benzene hydrogenation is presented, and the materials flow trend and heat exchange in benzene hydrogenation unit heat exchange system are analyzed based on the characteristics of reaction. Aiming at the problems existed in the original design that the quantity of heat of 130 ~C cyclohexane is not be utilized, and the cooling water is consumed in reducing the temperature of cyclohexane, the modification measure of adding benzene preheater is put forward. The feed- ing temperature of benzene enhances from 40 ℃ to 120 ~C after heating with 130 ℃ cyclohexane and the output of heat generated by benzene hydrogenation increases, so that the quantity of by-product steam increases by 0.5 t/h and the cooling water usage decreases by 8. 76 t/h, which derives from certain economic benefit. The unit operated steadily with longer period after modification and the ener- gy consumption is reduced.