Common kinds and technical features of the starting-up system for once-through boilers have been analysed and compared. The starting-up system with start-up drain heat exchange and recirculation has good behavior under extremely low load operation and for frequent start-up

being suitable for operation under medium load and for two-shift operation; The flashing type has bad behavior under low load operation and for frequent start-up

being suitable for power plants with basic load. There are unique advantages and obvious deficiencies in practical operauion of each kind of starting-up system. Hence

it is necessary to comprehensively consider the factors

such as technical features

capital investment

and operation mode of power plants etc. for selecting the suitable type of starting-up system.