Currently there are two kinds of solutions to drive induced draft(ID)fans:driven by electric motor or turbine.Driven by electric motor will bring issues like service power consumption rate increasing

over large starting current and so on.While driven by steam turbine has relatively high initial investment and complex operation and maintenance systems.Combined with the actual condition of an ultra supercritical 660MW unit

comparison of technical economy between motordrive and turbine-drive mode of ID fans were conducted

from the system configuration

equipment selection

investment difference

power generation cost and payback period and other aspects.The results show that

both the above two drive modes were feasible in technique.Compared with the motor-drive mode

the steam-drive mode had a shorter payback period(4.7years)

but with a more complex system

higher comprehensive investment

greater workload of site operation and maintenance

and lower small steam turbine efficiency.The steam-drive mode would increase the standard coal consumption for power generation and the generation cost.Therefore

this ultra supercritical 660MW unit should adopt the motor-drive mode.