| 摘要 |
PURPOSE:To prevent the stress corrosion crack of a low-pressure steam turbine by a method wherein oxygen or hydrogen peroxide is poured into condensed water or feed water while deoxidizer is poured into a steam at the entrance of a steam turbine. CONSTITUTION:Condensed water in a condenser 1 is sent by a condensed water pump 2 into a desalting device 3 of the condensed water to clean it and is sent by a condensed water boosting pump 4 into a water reserving tank 6 through a low-pressure heater 5. Feed water in the water reserving tank 6 is supplied by a feed water pump 7 to a high-pressure heater 8 and a boiler 9 and is changed into steam. The steam is supplied to a high-pressure turbine 12a through a superheater 10 to work in the high-pressure turbine, then, is sent into a reheater 11 to heat it again and, thereafter, is sent into a medium-pressure turbine 12b and, further, to a low-pressure turbine 12c to work therein, then, is returned into the condenser 1 and is changed into the condensed water. Oxygen or hydrogen peroxide is poured into the outlet port of the condensed water boosting pump 4 through an oxygen pouring system 13. Deoxidizer is poured into the inlet port of the low-pressure turbine 12c through a deoxidizer pouring system 14. According to this method, excellent protecting films are formed in water and steam system by the existence of dissolved oxygen while the stress corrosion crack of the low-pressure turbine can be prevented by the removal of the dissolved oxygen. |
