On the basis of heat transfer characteristics of working fluid at different pressures inside the water wall tube and structure of the ultra supercritical 1 000MW unit once through boiler in Jianbi Power Plant

the varying phase transformation point method was adopted to establish the moving-boundary dynamic simulation model of water wall in ultra supercritical once through boilers

especially the length variation of hot water section

evaporation section and superheat section against the load changing.On this basis

the real-time dynamic simulation model for ultra-supercritical 1 000 MW unit boiler in Jianbi Power Plant was built on the STAR-90simulation platform.The dynamic and static characteristics test showed that

this model can simulate the unit's startup/shutdown process and some typical fault conditions accurately

and had good dynamic and static performance.