WATER TREATMENT OF ULTRA-SUPER CRITICAL THERMAL POWER PLANT

摘要

PURPOSE:To decrease the amt. of Fe in feed water and to prevent sticking of corrosion product to a feed water system by measuring water quality in the inlet of a high-pressure feed water heater of an ultra-super critical thermal power plant, feeding a liquid chemical into the feed water system and adjusting the pH of the feed water. CONSTITUTION:The amt. of Fe and pH of feed water are measured in the inlet of a high-pressure feed water heater 13A of an ultracritical thermal power plant which feeds the condensate from a condenser 2 of a turbine 1 through a condensate desalting device 6 and low-pressure feed water heaters 8A-C to a deaerator 9, supplies the feed water from a water storage tank 10 thereof by a boiler feed water pump 12 through high-pressure feed water feeders 13A-C and a fuel economizer 14 to a boiler 15 and introduces the generated steam into said turbine 1. A chemical such as aqueous ammonia, hydrazine or the like is fed into the feed water from either or both of chemical feeders 21B, 21A in the inlet of the heater 13A or the inlet of the heater 8A according to the measured values to adjust the pH of the feed water to 9.5-9.8. Sticking of the corrosion product to the apparatus, piping, etc. of the feed water system is thus prevented and the efficiency of the plant is improved.