Steam blowing is an important construction link relating to safe and efficient operation of power generating units. However

the reduced pressure steam blowing system of double-reheat units is complicate

the tube blowing is too frequent

the effective tube blowing time is short

and the tube blowing duration is also long. To solve these problems

combing with the parameter characteristics of the thermal system

this paper proposes an optimization scheme in the reduced pressure steam blowing system design. In this method

the superheater system and the primary reheater system are regarded as a whole

and the temporary blowing valve is set at outlet of the primary reheater. This scheme is superior to the conventional way setting the temporary blowing valve at the superheater outlet

and can greatly increase the heat storage capacity of the boiler at blowpipe time

thus to raise the blowing efficiency and quality.