R&R Consult played a key role in making Nordjylland Power Station the world’s most efficient coal-fired CHP plant. The plant is Europe’s fourth-largest generator of electricity and owned by the City of Aalborg. We have been involved in several projects for Nordjyllandsværket concerning the optimization of different parts of the process.

One of our projects was to investigate the exhaust gas flow distribution in the desulphurization plant at Nordjyllands Power Station. Due to the complicated duct structure for the exhaust flow it was suspected that the flow distribution would be very uneven distributed, and this results in a reduced efficiency for the desulphurization process. R&R consult was involved in modelling the complete exhaust flow and the injection, tracking and evaporation of the slurry flow. Based on our work and recommendations, changes were made to the exhaust flow path and the slurry injection. The result of this was very successful with an improved desulphurization process and a reduction of the power consumption for the slurry pumps by 30 %.

The inlet exhaust flow distribution was predicted by including the upstream ducting and this revealed an uneven distribution and the transition duct into the desulphurization plant enhanced the uneven distribution. The inlet flow distribution was improved, based on the findings from the CFD simulation.

The modelling included a 3D Turbulent two-phase transient coupled calculation, including evaporation, breakup and collision of the slurry droplets. The initial droplet size distribution, at the exit of the slurry pipe, was based on emperical relations.