For the desulfurization wastewater zero discharge technology of evaporation and crystallization in flue gas in main flue duct and bypass of a newly built ultra-supercritial 660 MW unit belonging to Huaneng Group Co.

Ltd.

the technological process and control strategy of this technology are depicted at first. Then

the changes of parameters with the operating of zero discharge technology

including air preheater

feed water after the primary economizer

low-temperature economizer and the main steam

are studied by tests during the commissioning. The effect of this desulfurization waste water zero discharge system on the electric precipitator

water consumption of desulfurization system

liquidity and quality of coal ash are analyzed finally. The results show that

this technology has limited effect on temperature of the feed water behind the primary economizer

flue gas at outlet of the air preheater

hot primary and second wind

as well as the quality of coal ash. Therefore

this zero discharge technology is of extensive value and worthy of promotion with the advantages of safety

energy conservation and high efficiency.