METHOD AND SYSTEM FOR CONTROLLING WATER QUALITY IN POWER GENERATION PLANT

摘要

A method of controlling water quality in a power generation plant which includes a low-pressure feedwater heater (18), a deaerator (19), and a high-pressure feedwater heater (20) that have been successively disposed in a water supply line (16) extending from a condenser (15) to a steam generator or boiler (11), and in which the quality of feedwater to be led to the steam generator or boiler is controlled. The method comprises: injecting an oxidant from an oxidant injection line (31) into the feedwater flowing within the water supply line on the downstream side of the condenser, so that this feedwater comes to have a dissolved oxygen concentration of 3-100 ppb while being kept neutral, thereby forming an oxide film on the surfaces of the structural materials of the water supply line, low-pressure feedwater heater, deaerator, high-pressure feedwater heater, etc. which come into contact with the feedwater; and injecting a deoxidizer from a deoxidizer injection line (35) into the feedwater flowing within the water supply line on the downstream side of the deaerator, so that the feedwater flowing into the steam generator or boiler has a dissolved oxygen concentration of 5 ppb or lower.