Numerical Study Of Gas-solid Hydrodynamic Characteristics In A 600MW Supercritical CFB Boiler

As a high efficient and clean combustion technology, circulating fluidized bed boiler has developed rapidly in recent years with the steam parameters advancing towards supercritical level. China is developing a 600MW supercritical circulating fluidized bed boiler which has not yet put into operation in the world. Under the support of Fluent commercial software, this paper simulated the hydrodynamic characteristics of a CFB cold-test bed and a 600MW supercritical CFB boiler using Two-Fluid Model (TFM) combined with the Kinetic Theory of Granular Flow (KTGF). This paper is devoted to provide reference for the design of 600MW supercritical CFB boiler.Based on a review of the current situation of supercritical CFB boiler and numerical simulation of CFB boiler, this paper introduced the application and basic theory of Two-Fluid model combined with KTGF.The defects of common drag coefficient correlations were analyzed and the approach according to the modified Energy-Minimization Multi-Scale model (EMMS) was introduced. This paper presented a model of CFB external circulation carried out by UDF and a method of modifying SA nozzle for correcting the effect of temperature swift change. The basic treatments for simulation of CFB boiler were also proposed.Two different drag coefficient correlations were adopted in the simulation of a CFB cold-test bed and the results were compared with experiment. The influence of different SA ratio and static bed height were studied in this paper, presenting a good fit with experiment.At last, a 600MW supercritical CFB boiler was simulated to represent the axial and radial distribution of particles, the influence of cage division wall and platen superheater, the nonuniformity of the six separators and the penetration performance of SA.