Intake heating system for combined cycle power plant and control method thereof

The invention discloses an intake heating system for a combined cycle power plant and a control method thereof. The intake heating system comprises a low-pressure steam pocket, a low-pressure heatingspiral coil assembly, a high-pressure steam pocket, a high-pressure heating spiral coil assembly, a filter, a flash vessel, a regulating valve and the like. According to the intake heating system andthe control method thereof, the low-pressure heating spiral coil assembly and the high-pressure heating spiral coil assembly are heated through continuous blowdown of the high-pressure steam pocket and the low-pressure steam pocket of a boiler of the combined cycle power plant, the intake heating temperature is higher, and the economical efficiency is better; additional power equipment is not needed, and the equipment and daily maintenance investment is lowered; cascade heating is more reasonable, sewage can be conveniently discharged in a converged mode due to the inclination angle with the lower front portion and the