The invention relates to a 
quick start method and 
system of a 
combined cycle unit, which mainly detect and control the PH value of the 
condensed water by controlling the dissolved 
oxygen in the water and steam of a 
thermodynamic system and controlling the dissolved 
oxygen corrosion according to the relationship among temperature, pressure and content of dissolved 
oxygen of water and steam, by setting the content of dissolved oxygen in the 
condensed water to be less than or equal to 50
microgram / L and by setting the content of dissolved oxygen in the water feed to be less than or equal to 15
microgram / L, and adopts the combined deoxygenization manners of condenser vacuum deoxygenization and chemical dosing deoxygenization, and optimized 
operation mode and 
maintenance mode to ensure that the 
oxygen content in the 
condensed water in the 
combined cycle unit reaches the standard so as to avoid 
oxide etch of the 
metal due to that the 
oxygen content in the condensed water of the unit is excessive. The 
quick start system used for the 
combined cycle unit comprises a condenser; the water outlet of the condenser is connected with the input end of a condensed 
water flow meter through a condensed water pump and a shaft-sealing cooler; one loop of the outlet end of the condensed 
water flow meter is communicated with a boiler of the combined cycle unit through a condensed 
water cut-off valve, and the other loop is connected with a water return port of the condenser through a recycle 
cut-off valve and a recycle control valve; and a steam outlet of the condenser is connected with a 
vacuum pump through an air valve. The 
quick start method and 
system have the advantages that the overall structure of the 
thermodynamic system is simplified and the reliability and the economical efficiency of the system are improved.