超低排放燃煤电站SO3生成及全流程分布特性

对多个电厂省煤器出口和SCR出口烟气中SO3浓度进行了测试，并对两个典型超低排放1000MW机组50%、75%和100%负荷烟气中SO3浓度进行了全流程现场实验，主要研究典型燃煤电站中三氧化硫的生成和全流程分布特性。结果表明，三氧化硫炉内生成率一般在0.145%-0.785%之间，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三氧化硫的脱除率分别9999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2.48-3.36mg/Nm3。采用高效脱硫除尘一体化装置的燃煤电站三氧化硫总脱除效率为59.3-62%，最终排放浓度为6.8-8.6mg/Nm3。

Generation and Distribution Characteristics of Sulfur Trioxide in Coal-fired Power Plants with Ultra-low Emission

To investigate the generation and emission of SO3 in power plant, the sulphur trioxide concentration in several power plants are sampled and measured. The results show that the formation rate of sulfur trioxide in furnace is generally between 0.145% and 0.785%; the generation rate of sulfur trioxide in SCR device is 0.165-0.86%. After air preheater, the concentration of SO3 decreased by 18.3-28.1%.The removal rates 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 The combined method of wet desulfurization and wet electrostatic precipitator, the total SO3 removal efficiency is 61.2-76.4%, and the final emission concentration is 2.48-3.36mg/Nm3. While the total removal efficiency of sulfur trioxide in ultra-low(ULE) power plant with integrated wet dust-removal and desulfurization equipment is 59.3-62%, and the final emission concentration is 6.8-8.6mg/Nm3