The practical possibilities of steam temperature dynamic models application

This paper presents some experiences from the procedure of application of the heat processes simulation models. The main focus is on the steam production and superheating area with their control circuits in the power plant. The model was developed for the support of the full process from the initial design plans phase to the development of new control algorithms. The paper shows the main results achieved by the building of nonlinear dynamic simulation model of water-steam circulation part of once-through boiler. Also some significant steps in the process of the model verification are demonstrated. The verification process was split into several steps. The main focus was on the final behavior of superheaters with control circuit, but also on some partial steps that had to be done (e.g. tests of the model nonlinearity, tests of the water-steam attemperator, etc.). Additionally, the results from the main application are presented. The standard cascade-base quasi-adaptive control algorithm was tested in many standard situations (e.g. primary and secondary control simulation tests), in reactions on common disturbances and in a case of some specific operation errors or disturbances, too. The model has been used to the development of alternative possibilities of control (MPC, robust control). Finally, significant results from tests and development of new control algorithms are discussed.