Researches On Anti-surge Control Strategy Of Centrifugal Compressor Based On Control Performance Assessment

Centrifugal compressor is an essential equipment in many industry fields, such as metallurgy and petroleum chemical. Although centrifugal compressor has many advantages, but it also has some shortcomings that hard to overcome. For example, the stable working area is narrow, the compressor is easy to enter surge region, etc. When the compressor is working in unstable small flow region, the surge phenomenon may happen. This phenomenon can cause pressure and flow periodicly 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 work of Harris who presented a 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. The Recycle Trip Line (RTL) in the anti-surge control strategy is setted by human experiences, and lacks of theoretical basis. This paper focuses on the above problems, and presents an anti-surge strategy based on performance assessment.The basic idea of the anti-surge strategy is:using the time series analysis method to establish a time series model. Extracting a feedback invariante, 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 change the strategy from PI control to recycle trip.The simulation results show that the proposed strategy can meet the actual situation, and has practical and simple characters.