The mathematic model of dynamic behavior for once-through boiler of supercritical 600 MW unti in Qinbei Power Plant has been established

including the lumped parameter model of single-phase heating pipes

the lumped parameter model of pressure-flow rate passage for single-phase heating pipe

the lumped parameter model of two-phase heating pipe sections

the exothermic model of flue as side

the model of spray desuperheater

and the model of steam turbine etc..Through numerical emulation

the dynamic behavior of said boiler has been studied

the stability of dynamic response

the amplitude of said response after any disturbance

such as step increase of 5% in feed-water temperature

in feed-water flow rate

in fuel coal amount

in spray water flow for desuperheating in superheater and reheater etc.

as well as the influence of said disturbances upon dynamic behavior of the boiler

have been analysed

providing certain guiding effect for manufacture

operation

and control of supercritical once-through boiler.