Design For Propylene Compressor Control System

During the production process, instrumentation and control systems shall closely monitor the pressure, temperature and vibration, etc. Base on this feedback information, the system handle abnormal situations automatically and quickly to protect that the compressor is running stable and prevent any abnormal vibration. Therefore, the design of a reliable instrumentation and control system with high security level for propylene compressor train is particularly important.This paper takes its source from engineering project cooperating with methanol synthesis unit for Inner Mongolia Rongxin Chemical Co., Ltd. This project selected refrigeration station and refrigerating system compressor train 3MCL707 from Shenyang Blower Works Group Co., Ltd, driven by NKS40/46/20 steam turbine from Hangzhou Turbine Co., Ltd.This topic analyses the operating principle of propylene compressor train, and research on its surge mechanism. According to process requirement and system design standard, it analyses the local instruments of the compressor unit, and design proposal of standardize model selection. Design I&C system for propylene compressor train. On that basis, it research on monitoring and protection of compressor bearing vibration and shaft displacement, to complete startup by frequency doubling and complete system scheme of monitoring and protection of the train. Considering low temperature of medium at compressor suction, automatic temperature control system was developed. Propylene compressor train is centrifugal compressor driven by steam turbine. All measuring points in steam turbine, propylene compressor and dry gas seal shall be connected to combination control system of Turbine compressor train, therefore, this paper also studies on some important logic model of propylene compressor train. As per its process feature, accomplish its process design. At last, base on working philosophy of TRICON, discuss the importance, necessity and the reliability of redundancy control system, to improve the design of propylene refrigerating compressor control system.This paper describes the design of I&C system for propylene compressor train and it comes up with surge preventative measure, and introduce fast line and anti-surge line. This practically reduces the chance of surging and achieves satisfying result.