Analysis and validation of CFD simulations for flow in the large power station flue gas system

Abstract

This paper deals with complex CFD simulations of flows in the flue gas system of a large power plant during operation. The aim of the published results is to present generalising knowledge obtained from complex simulations in the power station and show aspects for relevant modelling of large real systems. The computational models covered the flue gas system between the boiler and the flue gas fan. The CFD simulations were run in more model modifications and the results were used to evaluate the distribution of velocities, temperatures and solid pollutants. Relatively unique complex measurement allowed to validate the results of the simulations. The comparison of simulated and measured velocity profile in the large vertical channel with internal beam reinforcement system shows satisfactory agreement. The CFD model of the Ljungström-type air preheater at various rotation speed was used for prediction of the temperature distribution before the six electrostatic precipitators. Computed distribution of flow-rates on inlets and outlets of electrostatic precipitators were also validated by measurement. Based on good agreement was made a study of setting the outlet flap valves for balancing of flow-rates. The setting was satisfactory validated again. The results of study have shown that CFD simulations can be deployed even on large-sized flue gas pipelines with sufficient reliability if important parameters are respected.