| Nowadays, Turbine Compressor are widely applied in oil refining, natural gas, coal chemical industry and other industries. In particular, the compressor, as core equipment of a diesel hydrogenation plant, does need safe and stable operation, once a failure happens, there will be very serious consequences. Therefore, providing an intelligent control system for the core equipment is like providing a brain for the compressor unit. On the basis of guaranteeing smooth running of the compressor unit, it saves energy to the maximum, and optimizes the control scheme to ensure safe operation of the plant.In the context of development of control system of compressor of diesel hydrogenation plant of PetroChina Ningxia Petrochemical Company, this paper gives a detailed introduction of the operating principle of steam turbine and compressor. The control system in this paper adopts Tricon control system manufactured by TRICONEX. Triple redundant fault-tolerant controller further improves the performance and stability of control system. This paper completes the scheme for design of control system of compressor, and gives a set of useful compressor control strategies. Aiming at the speed control scheme, cascade control is exercised. The compressor unit is controlled by changing the setting value of inlet pressure, manual setting speed is target speed, target speed serves as SP value, measured speed serves as PV value, and valve opening value CV is obtained by constant comparison of speed PID of both. Compared with previous simple regulating system, cascade control system improves the control quality.Anti-surge control in this paper adopts control of variable limit flow method to replace previous fixed anti-surge control system. It includes multiple control loops, and better considers possible factors during the operation of compressor, thus improving safe reliability of anti-surge. Besides, it reduces energy wastage. The control scheme is improved during trial run of the plant, anti-surge control valve is opened when the system pressure is low, and the valve can be timely closed to the designated position after full-load. It ensures the circulation machine does not operate in the surge area whether full-load or no-load operation, which not only shortens the time of start-up and shut-down, but also saves the trouble of repair. Previous translation mode of anti-surge curve is improved to involute mode of anti-surge line, which improves the operating efficiency of the compressor unit, and realizes more stable control. It not only reduces energy consumption, but also brings great economic benefits for the enterprise.The diesel hydrogenation control system in this paper has gone into operation. Featured by smooth running, accurate control and easy operation, the control system fully meets and even goes beyond user requirements at the beginning of the design, and wins recognition and favorable comment from users. |
