The off-design modelling of a combined-cycle power plant

Abstract

The objective of this project was to develop a model of a combined-cycle power plant in Flownex which can be solved in off-design conditions in order to compare it to plant data. The verification of this model will show that Flownex can be used to effectively and efficiently model a combined-cycle power plant. The process of development of the final Flownex model was achieved using various additional software. Initially, an analytical model was developed in Mathcad (software used for engineering calculations). Thereafter, a model was built in Virtual Plant, a thermodynamic modelling software for assessing plant performance. Finally, the Flownex model was designed. For the single, double, and triple pressure combined-cycle power plant systems, the analytical, Virtual Plant and Flownex models were compared. The results of all the models agreed closely with one another. The triple-pressure design and off-design Virtual Plant and Flownex models were also compared to plant data and it was concluded that Flownex was successful in modelling the design and offdesign conditions of a combined-cycle power plant.