Regulační model přehříváku páry a jeho ověření na elektrárenském bloku 200 MW elektrárny Dětmarovice

Abstract

This dissertation thesis deals with modeling and simulation of control circuit of the output steam superheater which is a part of coal-fired boiler in Dětmarovice power plant. Dynamical behavior of the output steam superheater is described by partial differential equations for heat transfer between two media.

Mathematical model of the output steam superheater can be modeled as serial connection of two types of the systems. The first one is a concurrent steam superheater representing heat transfer between flue gas and steam through the superheater wall. The second type of the system represents mathematical model of heat transfer between steam and material of ideally isolated pipeline. This system referred to as an unheated area, serves for technological connections between steam superheater and surroundings components such as mixers and other heat exchangers.

The work includes creation of the control circuit for the output steam superheater and simulation results are verified by testing with the real operational data from the power plant. One of the aspects of use of mathematical model of steam superheater is determination of how the dynamical behavior of real boiler is affected by hardly measurable or non-measurable signals. Examples of such signals could be the flue gas temperatures of particular heat exchangers. The signal of flue gas temperature is calculated based on mathematical model of the superheater, followed by determination of how this signal affects the output stem temperature for various parameters of the flue gas.