Modeling And Optimization Control On Feed-Water System Of 600MW Super Critical Unit

Over the next 20 to 30 years, the optimization of the thermal power structures will mainly focus on energy saving, water saving and environmental protection, thus developing supercritical unit that with large capacity, high efficiency, low pollution,excellent peakload performance will become the trend of future. Water supply system as one of the important control systems for supercritical units, its quality directly affects the safe and stable operation of the boiler water system. In order to improve the control level of feed-water control system, we must have a deep understanding about its thermal characteristics, and establish a model suitable for control strategy research based on that understanding. Water supply system with multi variable,strong coupling, large inertia and large delay characteristics, and usually site disturbance tests are not allowed, so the traditional modeling methods can not meet the requirements of the control system. The new control system are widely used, so that a large number of field data can be saved and viewed in real time. Through analyze the vast amounts of field operation data, digging out of a lot of useful information. At the same time the unit simulation technology has been able to simulate field operation characteristics, that provided favorable conditions for modeling and optimization feedwater control system.In this paper, a power plant 600 MW supercritical unit feedwater control system is being researched. Supercritical unit feedwater control system is complex, it is difficult to control as a whole, therefore we need a modular system processing, and split the complicated system into a simple small modules. The system structure and reaction mechanism of this system are analysised to establish the mathematical model of the main parameters and equipment. Based on the simulative Simuplat simulation support system of virtual DCS platform, the mechanism of the water supply system modeling are realized. Secondly collect extensive field data, to extract useful data for experiment model after data preprocessing, and select historical data of different run time under the same conditions to verify the accuracy of the model. In case to optimize the main and auxiliary controller parameters of cascade water supply control system based on enthalpy, particle swarm optimization algorithm is applicated and finally got the ideal control effect. Results prove the reliability of the model, and provides a feasible reference for scene control and optimization schemes.