【摘要】 燃煤电站中SO₃的生成、转化和排放特性引起广泛的关注。为了研究燃煤电站中SO₃生成及全流程分布特性,对多个电厂省煤器出口和选择性催化还原（SCR）出口烟气中SO₃浓度进行了测试,并对两个采用不同超低排放技术路线的1 000 MW机组的SO₃浓度进行了全流程现场实验。结果表明,SO₃炉内生成率一般为0.145%～0.785%,SCR装置内SO₃生成率为0.165%～0.86%。空预器后SO₃浓度降低,降低幅度为18.3%～28.1%;传统静电除尘器和低低温静电除尘器对SO₃的脱除率分别为7.5%～10%和20.2%～31.4%。传统湿法脱硫装置和高效脱硫除尘一体化装置对SO₃的脱除率分别为22.2%～29.5%和26.2%～36.7%。采用湿法脱硫+湿式静电除尘器的组合方式实现超低排放的燃煤电站对SO₃的总脱除效率为61.2%～76.4%,最终排放浓度为2.48～3.36 mg/Nm³。采用高效脱硫除尘一体化装置的燃煤电站SO₃总脱除效率为59.3%～62%,最终排放浓度为6.8～8.6 mg/Nm³。更多还原

【Abstract】 The generation, transformation and emission characteristics of sulphur trioxide（SO₃） in coal-fired power stations have attracted broad attention. In order to study the SO₃ generation in the coal-fired power plant and the distribution characteristics of the whole process, the SO₃ concentration in flue gas from economizer outlet and outlet of several power plants were sampled and measured. The site experiment on SO₃ concentrations of two 1 000 MW units with different ultra-low emission technology routes was conducted. The results show that the generation rate of SO₃ in furnace is generally between 0.145% and 0.785%, while that in SCR device is 0.165%～0.86%. After air preheater, the SO₃ concentration decreases by 18.3%～28.1%.The removal efficiency of sulfur trioxide by conventional electrostatic precipitator and low-temperature electrostatic precipitator are 7.5%～10% and 20.2%～31.4%, respectively. The removal rate of SO₃ by conventional wet desulfurization device and efficient desulfurization and dust removal integrated device is 22.2%～29.5% and 26.2%～36.7%, respectively. For ultra-low（ULE） power plant with wet desulfurization and wet electrostatic precipitator, the total SO₃ removal efficiency is 61.2%～76.4%, and the final emission concentration is 2.48～3.36 mg/Nm³. While the total removal efficiency of sulfur trioxide in ULE power plant with integrated wet dust-removal and desulfurization equipment is 59.3%～62%, and the final emission concentration is 6.8 mg/Nm³～8.6 mg/Nm³.更多还原