Abstract: The bypass flue evaporation treatment process for desulfurization wastewater from coal-fired power plants is of
low cost in investment and operation，and easy to operation. Its performance is affected by many factors such as unit load，
flue gas temperature，and flue gas field. An optimization design is made on the bypass flue evaporation system in a 300
MW coal-fired power plant based on the gas indexes，variations of wastewater quality and quantity. According to the
operational parameters of the bypass flue evaporation system，it runs stably and meets the designing requirements. With 4.5
m3/h water evaporation quantity，the mass fraction of chloride ions in pulverized fuel ash after desulfurization wastewater
evaporation process is within 0.25%，which will not affect the comprehensive utilization of pulverized fuel ash，but will
decrease the boiler efficiency by approximately 0.43 percentage points. In order to minimize the impact on the boiler
efficiency，the desulfurization wastewater should be concentrated and reduced.

Key words: desulfurization wastewater, bypass flue evaporation, 300 MW coal-fired power plant, flue gas temperature,
water quality, water quantity, pulverized fuel ash, zero discharge