Abstract: Abstract:The feed water control is one of the important control systems of supercritical once through boiler. To establish an accurate mathematic model for water supply system of supercritical unit is an important foundation of ensuring water supply control quality. It is difficult to identify more accurate model by using of traditional identification method due to the complexity of supercritical once through boiler. Aiming at the features of the supercritical unit and the shortcoming of the traditional identification method, the standard particle swarm optimization method was used in water supply process identification. Taking a 600MW supercritical unit as example, based on the practical operation data of the power plant, a transfer function between the specific enthalpy of separator outlet (middle point) and the feedwater flow was established. The verification results show that the identification model can reflect actual operation curves accurately, which provide premise and assurance for design of water supply system of supercritical unit. Simultaneously, the rapidity and the accuracy of the identification model were improved by the particle swarm optimization method.

Key words: Keywords:supercritical unit, water supply system, particle swarm, identification, specific enthalpy, feedwater flow, transfer function