| Steam power plant is the main power plant of a large ship, which have several advantages, such as larger unit capacity, better adaptive ability of fuel. Steam power plant plays a decisive role in ship's operating, speed, endurance and other important technical performance. When steam power plant is operating, frequent changes in the load, large margin, the control system in response to the high performance requirements, so well-designed control system is very necessary. Turbine often had to make changes within a wide range of operating conditions, sometimes direct to parking from rated speed, and sometimes directly leaping from the parking to a state of speed. In this way, the steam power plant must bear to the impact load. Compared with boiler in thermal power station, the main boiler in ship was smaller and less heat storage capacity. If there was no reasonable coordinated control system, the main boiler will be difficult to meet the frequent changing requirements of he load.The Boiler and Turbine is a whole with a relative independence, therefore, Coordination Control System (CCS) should take full account of boiler and turbine's features make full use of the boiler's heat storage capacity and turbine's rapid regulating ability. Not only ensures the turbine could be quickly adapted to load changes, also without causing large fluctuation of main steam pressure.In this paper, a new CCS is introduced according to the dynamic characteristics of the boiler-turbine system, based on boiler-follow-turbine. Unidirectional decouple method is been used for decouple the MIMO system, then the turbine side become a single variable system, PID Neural Network is used to control this side. In boiler side a neural network internal model control system is established, PID neural network is used for building the internal model and controller. Finally the simulation results show that: The boiler-turbine system has been better control. |
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