The scaling-up characters are important technical problems for large-capacity circulating fluidized bed(CFB) boilers

the basic principle of scaling-up design for CFB boilers and the calculation formula for effective height of the furnace have been studied and put forward.In scaling-up design of the furnace

it is required to investigate the characters of internal process in the furnace

such as the penetrability of secondary air

the diffusive uniformity of feeding coal and circulating ash

and the flow stability of gas-solids etc.

the key technologies of scaling-up design for CFB boilers have been analysed.Through test on practical CFB boilers and numerical simulation

the scaling-up design of CFB boilers can be conducted

and the most economic structural size with optimal performance of boiler can be determined.The compact design is an important tendency of large-capacity CFB boilers

the compact design method for key components

i.e.external heat exchanger and cyclone separator etc.

have been analysed and discussed.