On the basis of thermal system in conventional ultra-supercritical power generation units

a design scheme for a master cycle(MC)system was proposed.In this scheme

the steam extraction from the intermediate pressure(IP)cylinder is replaced by extracting steam from an added regenerative small steam turbine.Taking an ultra-supercritical 1 000MW unit as the example

the EBSILION software was applied to conduct thermodynamic and economic analysis for the conventional system and MC system under different working conditions.The results show that:the power generation efficiency of the unit applying the MC system is 0.15%and 0.24%higher than that using the conventional system

and the coal consumption rate is 0.92g/(kW ·h)and1.61g/(kW·h)lower

under design condition and 30%load condition

respectively.Thus

the ultra-supercritical unit employing MC system is more suitable to work under low-load working conditions.