Air Separation Unit Air Compressor Anti-surge Control System

Centrifugal compressor is very important in the production process, to solve the quality and efficiency of the compressor operation has great significance. Centrifugal compressor surge is the inherent characteristics, it will bring very serious harm to whole control system, even follow-up system and mechanical systems. The traditional use of PID control of centrifugal compressor surge, with some limitations, the performance depends on the parameters of the entire set, and the speed and the contradictions between the overshoot, and often open the anti-surge valve can cause a waste of energy; as fuzzy control, while maintaining fast, can guarantee a smaller overshoot, while the speed of adjustment is a decrease of anti-surge valve is opened the number of times, saving the consumption of the anti-surge valve of energy. In this paper, with the actual situation of centrifugal compressor control system in air separation plant in ammonia plant of a company, following studies to the centrifugal air compressor anti-surge control is conduced.Firstly, overview the centrifugal compressor anti-surge control technology and anti-surge control system development status and trends.Secondly, explore the compressor performance curve, load type, surge hazards, and detailed analysis of the characteristics of the compressor surge to arrive surge of influencing factors.Finally, the anti-surge control system, established the anti-surge control algorithm, and carried out with the Simulink simulation. Control system includes speed adjustment control, and anti-surge valve fuzzy control.Speed adjustment control with space vector control of synchronous motor speed control strategy, and using SVPWM technique. Speed adjustment control reduce the anti-surge valve is opened the number of times, saving the loss energy due to return.Anti-surge valve fuzzy control, using fuzzy control method to design fuzzy anti-surge controller, and use Simulink software package for anti-surge valve fuzzy control system of the simulation, results show that fuzzy control can address the surge issue.