脱硫废水烟道蒸发工艺对烟气酸露点影响分析  

Analysis on the Influence of the Wastewater Evaporation in Flue Duct to the Flue Gas Dew Point

作　　者：吴智泉 曹蕃 袁园 贾西部 WU Zhiquan;CAO Fan;YUAN Yuan;JIA Xibu(China Datang Corporation Science and Technological Research Institute,Beijing 100043,China)

机构地区：[1]中国大唐集团科学技术研究院有限公司,北京100043

出　　处：《中国电力》2019年第1期151-155,184,共6页Electric Power

摘　　要：为研究脱硫废水烟道蒸发工艺对烟气酸露点的影响,在某600 MW机组上进行烟道蒸发中间试验(中试),实测废水蒸发前后烟气中H_2O和SO_3浓度,并采用不同计算公式计算酸露点。中试结果表明:在空气预热器后1/4烟道中(烟气量为4×10~5～5×10~5 m^3/h)喷入900～1 400 L/h的废水时,烟气中的水蒸气质量分数增加了0.7～0.9个百分点,而烟气中的SO_3浓度却降低30%～50%,说明废水烟道蒸发促进了SO_3向硫酸雾的转化并促进了其在飞灰颗粒上的吸附;废水喷入烟道蒸发后,烟气酸露点反而有所降低,虽然烟气平均温度降低了9～14℃,但废水喷入后的烟温仍基本高于废水喷入后的酸露点,因而脱硫废水烟道蒸发不会造成下游烟道和设备的低温腐蚀。The effect of the wastewater evaporation in flue duct to the flue gas dew point was studied in this article.Pilot test of the wastewater evaporation was conducted on a 600 MW unit.The H2O and SO3 contents in the flue gas were detected and the dew point was calculated using different formulas.The results showed that,when 900~1 400 L/h wastewater was injected in 1/4 flue duct of the 600 MW unit(the amount of flue gas was 4×10^5~5×10^5 m^3/h),the water vapor in the flue gas increased 0.7%~0.9%,whereas the SO3 decreased by 30%~50%,which indicated that the transformation from SO3 to sulfuric acid mist and their adsorption on fly ash particles were improved after the wastewater evaporation.The flue gas dew point decreased by 9~14°C after the evaporation,and the flue gas temperature could be higher than the dew point.Thus,wastewater evaporation in flue duct could not lead to low-temperature corrosion of the downstream ducts and equipments under the condition of pilot test.

关 键 词：燃煤机组 脱硫废水 烟道蒸发 酸露点 SO3 

分 类 号：X773[环境科学与工程—环境工程] TM621.9[电气工程—电力系统及自动化]