Anti-surge Switch Control Of Centrifugal Compressor Based On Control Performance Assessment

Centrifugal compressor is essential equipment in many industry fields, such as metallurgy and petroleum chemical. Compressor is a device which converts the mechanical energy into the gas pressure, Surge is the inherent characteristic of the compressor. When the compressor is working in unstable small flow region, the surge phenomenon may happen. This phenomenon can cause pressure and flows periodically change. Furthermore, it may damage the bearings, seals, and cause serious accidents. Above all, making a correct anti-surge control strategy is very important to the safety operation of compressors.This paper is based on the generalized minimum variance benchmark to assess the performance of control systems. And the research object is CCPP gas system’s compressor in LuoJing power plant of Shanghai baosteel group. Through the deep research of the performance assessment method which is based on the generalized minimum variance control system and the working principle of centrifugal compressor, we find that the switch points in the anti-surge switch control strategy is setted by human experiences, and lacks of theoretical basis. This paper focuses on the above problems, and presents an anti-surge switch control strategy based on performance assessment.The basic idea of the anti-surge switch control strategy is using the time series analysis method to establish a time series model, extracting feedback invariants, and assessing the anti-surge PI control system. When the system performance index drops to a preset value, the performance of the control system becomes poor, the control system can not meet the requirement of the anti-surge control system. So we need to switch the control strategy from anti-surge PI control to valve recycle trip to ensure sufficient back flow. The simulation results show that the method has effective and practical characters.