Simulation of a Subcritical Power Plant using a Boiler Following Control sequence

The objective of this work is to model a pulverized coal power plant and some of its component units and to apply control based in the boiler following control approach, in order to analyse the control system and the power plant performance at different operational conditions. The ETI-CCS project comprises the modelling of the several components of the carbon capture and storage chain, starting with the pulverized coal power plant, the basis of the thesis. The modelling is developed in gPROMS and consists building some units to be added to the power plant library. Some of the models are grabbed from this library to be connected and to represent a pulverized coal power plant. The building of a flowsheet like the PCPP is a challenge, since the number of recirculations, between the great number of units, is great. By controlling the system, it was possible to represent, for example, the typical behaviour of the key variables of the system in load changes, representing the daily cycle. From the performance study it was concluded that for lower loads the power plant’s efficiency decreases, consuming more resources per MW, and that the coal’s LHV and the turbine’s efficiencies increase the net efficiency.