By adopting the ThermoFlex software

a model of a 200 MW level IGCC system based on two-stage coal-water slurry gasifier has been established

and the influence of load variation of the gasifier upon the gas turbine system

the steam turbine system

and the IGCC system being investigated.The results of investigation show that the mcreasing of secondary stage coal feed ratio(Ysc) can enhance the temperature of main steam and reheated steam

reducing the auxiliary power rate

making the power generating efficiency and power-supplying efficiency of the system to be heightened

as the gasifier is working under high load(100%

90%) condition;but in case of the gasifier working under lower load(80%

70%

60%)

the increasing of secondary stage coal feed ratio has few infuence upon the inlet temperature of gas turbine

the temperature of discharged gas

and the power-gene rating efficiency of gas turbine;along with increasing the secondary stage coal feed ratio

the power-generating efficiency and power-supplying efficiency of the IGCC system have a tendency of increasing at first and then decreasing

at this time

the superiority of system performance isn't remarkable.