Large ASU Air Cooling System Study And Optimization

In this paper, a large Air Separation Unit(ASU) air cooling system was studied and optimized. The ASU capacity is 60000Nm3/h Oxygen and is operating in YanKuang Cathay Coal Chemicals Co., Ltd. we summed up the key problems from nearly five years operation data that influence the long-period, high efficiency, safe and stable operation of the ASU. This paper focus on the problem as follows: In summer, the temperature of the outlet air of air-cooling tower in the purification system of the ASU is prone to too high and result in the penetration of the molecular sieve adsorbent, further causing the paralysis of high-load operation of the air separation system and then effect oxygen usage in the post system. So the long-term operation of air separation system could not be achieved. In addition, the molecular sieve adsorbent can't be completely regenerated in summer and need to be frequent special regenerated, which seriously affect the life of molecular sieve adsorbent and other production problems. Focusing on those production problems, we proposed means and specific programs to improve the operation of air separation unit stably and economically. We carried out a series of engineering reform and technological transformation process optimization and on-line clean-up operation processing operation of innovative and effective reduce the temperature of outlet air of air cooling tower, which greatly improved the operation conditions of the ASU, so as to provide a reliable guarantee of the ASU to run safely and stably in long period. According to the performance test data of before and after process improvement, optimizing the processing operation and the on-line clean method of cooling tower have achieved success firstly in our country. The achievement of pre-cooling purification system of the ASU design, operation, testing and transformation in this paper, can provide important theoretical guidance and practical reference for air separation industry.