Dynamic modelling and simulation of an industrial boiler system

The main objective of this thesis is to develop a first-principles dynamic model for an industrial boiler system. The purpose of the model was to provide--a means of investigating the dynamic behaviour, in particular the stability, of all industrial steam and power cogeneration system; a basis for the development of a simulator for operator training; and estimates of transient variations of metal wall temperatures at various boiler sections for use in studying boiler life expectancy.; A dynamic state space model for the boiler system including the utility boilers, the common steam header, and their controls has been developed. The dynamic model was based on the methods presented by Dieck-Assad (6), Rackette (20), and Kakac (13). A detailed description of the model development is provided in this thesis.; This model has been evaluated under both dynamical and in steady state conditions via closed-loop simulations. The overall energy balance of the model is correct--the fuel flow rates were within 2.28% and the flue gas exit temperatures were within 13.2% of those provided in a Syncrude report on the boiler system--for steam loads of 94.5 kgs, 100.8 kg/s, and 108.9 kg/s. The transient characteristics of the dynamic model were correct qualitatively. The responses of all the variables reached steady state within 1500 s using the actual PI controller parameters from the Syncrude boiler system implemented. The behaviour of important variables such as the steam drum and common header pressures, the fuel and air flow, and the temperatures of the flue gas and steam/water, in the various boiler sections also matched that observed in the real process.