燃煤电厂脱硫废水烟道物化蒸发数值模拟

Numerical simulation of physicochemical evaporation of desulfurization wastewater flue in coal-fired power plant

针对脱硫废水雾化处理技术,采用Fluent软件对山西某电厂350 MW机组空预器与除尘器间烟道进行数值模拟,根据数值模拟结果分别对喷入脱硫废水后烟温变化量及烟温对脱硫废水蒸发的影响进行了分析。结果表明:该烟道内喷入1 000 kg/h的脱硫废水致排烟温度降低3~4℃,且温降数值随入口温度的升高温而增大;升高烟气入口温度可有效提高雾滴完全蒸干比例,缩短雾滴的蒸发时间。研究工况下每提升烟温每提升1℃,脱硫废水蒸干比例可提升1.72%,脱硫废水蒸干极限时常缩短0.02 s。

For the desulfurization wastewater physico-chemical treatment technology, Fluent software is used to numerically simulate the flue between the air preheater and the dust collector of a 350 MW unit in a power plant in Shanxi. Influence and smoke temperature were analyzed on the desulfurization wastewater evaporation status. The results show that: after spraying 1 000 kg/h of desulfurized wastewater into the flue, the exhaust temperature reduced by 3~4 ℃, and the temperature drop will increase with the increase of the inlet temperature;increasing the inlet temperature of the flue gas can effectively increase the complete evaporation rate of mist droplets shortens the evaporation time of mist droplets. For every 1 ℃ increase in smoke temperature under the research conditions of this paper, the evaporation ratio of desulfurization wastewater can be increased by 1.72%, and the dehydration wastewater evaporation limit is often shortened by 0.02 s.