Coupled modeling of combustion and hydrodynamics for a 600 MW Bunsen-type boiler

Hydrodynamic calculation is considered to be significantly important to ensure the safe operation of boiler during the peak-shaving process. An accurate furnace heat flux distribution is the basis for the accurate hydrodynamic calculation. To investigate the hydrodynamic characteristics of a 600 MW boiler, a coupled model that consists of combustion simulation and hydrodynamic calculation is applied in this study. The numerical simulation could provide the distribution of the furnace heat flux as a preparation for the hydrodynamic calculation. Results show that the calculated value of the hydrodynamic characteristics agrees well with the measured one. The pressure drop differences of the steam system between the calculated and measured values are 0.04, 0.02, 0.13, and 0.05 MPa under 100% boiler maximum continuous rating (BMCR), 75% turbine heat acceptance (THA), 50% BMCR, and 30% BMCR loads, respectively. The relative error of the mass flux distribution increases as operating load decreases, reaching a maximum (7.63%) under 30% BMCR load. For the four loads discussed in this study, the greatest temperature of the working fluid is 681.0 K, while the fin-center temperature jumps from 708.0 to 801.7 K under 100% BMCR load. The present study is intended to improve the method of the hydrodynamic performance calculation, which would benefit the safety operation of boiler during the peak-shaving process.