Operation Characteristics of Fluidized Bed Heat Exchanger of Large-scale Circulating Fluidized Bed Boiler

In order to investigate the operation characteristics of fluidized bed heat exchanger(FBHE) of large-scale circulating fluidized bed(CFB) boiler,experiments were conducted on two 300 MW CFB boilers which have been put into commercial operation,including the effect of FBHE on the adjustment characteristics of furnace temperature and steam temperature of CFB boiler and heat transfer characteristics of FBHE.The results indicate that the furnace temperature of CFB boiler with FBHE is quite even along the height direction,and there is almost no change in temperature when the boiler operates at above 60% boiler maximum continue rate(BMCR),whereas the furnace temperature of CFB boiler without FBHE is quite different,such difference becomes more obvious with the boiler load decreasing.The opening of cone valve increases monotonously along with the boiler load increasing.In the condition of constant load,when the bed temperature rises superheater water spray and reheater heat absorption decreases but at a relatively low degree.At different boiler loads,the heat transfer coefficients of the different heating surfaces in FBHE of CFB boiler are different,which increase monotonously with the boiler load increasing.