A Simulation Model For Use In Testing A Fast-time Predictor Instrument For Benson Boiler Steam Temperature Control

Abstract

The work reported in this dissertation is aimed at determining a sufficiently accurate model for a section of a power station boiler plant so that at a later time, a fast-time predictor instrument may be designed and tested without interfering with the operation of an on-line boiler unit. The mode 1 required for the predictor instrument is a simplification of the simulation model. The instrument enables the o p e r a t o r to predict, in a short time, how an action taken now will affect the boiler unit in the future. It is suggested that such an instrument would enhance the operator's ability to control the boiler thus providing faster response times to system and grid disturbances. The dissertation includes a review of possible boiler control strategies. A motivation for a fast-time predictor instrument is provided. An analysis of mechanical engineering aspects of the boiler and of simulation techniques enabled a model satisfying the simulation objectives to be developed and Justified. A technique is suggested for determining the parameters for these models. An attempt was made to identify the- model parameters b u t , due to the limited data available and a suspected violation of the Nyquist sampling theorem, the attempt was not successful. Some recommendations are made for improving the quality of the data logged. It is concluded that a simulation model for the boiler processes can be obtained and that the parameter estimation technique is feasible, but that the complex task of system identification will require a considerable effort.