40万t/a合成氨装置(美国二手设备)凝气系统表冷器真空度偏低原因分析及技改措施

Reason Analysis of Vacuum on Low Side for Surface Condenser in Gas Condensing System of Synthetic Ammonia Plant(American Second-Hand Equipment) with a Capacity of 400,000 t/a

达州玖源化工有限公司40万t/a合成氨装置系于2007年引进的美国二手设备,2010年建成投产,但自原始开车以来一直存在表冷器真空度偏低的问题。介绍了装置凝气系统的组成和工艺流程;叙述了表冷器真空度偏低的情况;分析了真空度偏低的原因;提出了更新表冷器抽气器、改用中压蒸汽、替换疏水器等技改措施。结果表明,2013年1月实施技改后,表冷器的真空度由技改前的-72～-74.5 kPa达到-90.6 kPa,由此降低了凝气式透平的蒸汽消耗,可节约生产成本800万元/a。

The synthetic ammonia plant with a capacity of 400,000 t /a,in the Dazhou Jiuyuan Chemical Engineering Company Ltd.,was the second equipment imported from USA in 2007,it has been built and put into operation in 2010,but the problem of vacuum on low side in the surface condenser existed continually since original start-up.Author has introduced the constituents and process flow in the gas condensing system of the plant;has described the situation of vacuum on low side in surface condenser;has analyzed the reason of vacuum on low side;has presented the technical reformation measures of renewing vacuum-pumping vessel of surface condenser,changing to use middle pressure steam,replacing drainer etc.Result indicates that the vacuum of surface condenser can reach from-72 ～-745 kPa before technical reformation to-90.6 kPa after executing technical reformation in January in 2013,therefore the steam consume of gas condensing turbine can be reduced,it can save production cost by 8 million Yuan RMB annually.