Evaluation of the 200 MWe Tonghae CFB boiler performance with cyclone modification

The performance of the Tonghae CFB boiler with modification of the cyclone has been evaluated using the IEA-CFBC model. The effect of the cyclone efficiency on solid hold-up and pressure and temperature profiles in the combustor has been determined. From the calculated results, solid hold up in the lean phase of the combustor and pressure in the combustor increase, whereas solid hold-up in the dense phase and temperature in the combustor decrease as the cyclone efficiency increases. After modification of the cyclone through extension of the vortex finder and reduction of the width of the cyclone inlet duct, ΔPupper part and ΔPlower part in the combustor increase from 1328 to 1942 Pa and from 4402 to 4950 Pa, respectively. The temperature and the emission of SO2 of the combustor decrease after modification of the cyclone. Therefore, modification of the cyclone to improve its efficiency can allow operation and control of the Tonghae CFB boiler to be stable. The simulation results by the IEA-CFBC model can also explain well the improved performance of the CFB boiler.