摘要
燃煤电厂锅炉燃烧中SO2/SO3的转化率为0.5%~5%;超低排放条件下,SCR脱硝中SO2/SO3的转化率控制在1%以内。运行中为控制SO3在脱硝催化剂下层和空预器中的消耗,应尽量减少H2SO4和NH4HSO4的冷凝吸附,保证催化剂的活性及空预器的安全运行。理论上低低温电除尘器(LL-ESP)对SO3脱除效果显著,但不同工程实测表明,LL-ESP对SO3的脱除效率差别较大,介于1.8%~96.6%之间。此外,研究认为,电袋复合除尘器对SO3脱除效率为74.3%~85.9%。超低排放工况下,除空塔脱硫和海水脱硫技术外,大部分湿法脱硫技术对SO3的脱除效率高于50%;SO3在湿式电除尘器中的脱除效率也大于50%,但整体上与国外成熟案例相比稍有差距。总体而言,超低排放条件下,燃煤硫分低于1.5%时,燃煤电厂全流程环保净化设备对SO3的综合脱除效率高于90%,大部分机组的SO3排放浓度低于5 mg/m^3。
The conversion rate of SO2/SO3 is 0.5%~5% in boiler combustion, but it can be controlled within 1% in SCR DeNOx in coal-fired power plant. In operation, to control the consumption of SO3 in the sub-layer of SCR catalyst and air pre-heater in operation, the condensation adsorption quantity of H2SO4 and NH4HSO4 should be reduced as much as possible, which is aimed at protecting the catalyst activity and ensuring the safety of air pre-heater operation. Theoretically, the low-low temperature electrostatic precipitator has the excellent removal efficiency for SO3. However, the efficiency may changes from 1.8% to 96.6% in different projects. Study shows that the electrostatic-bag filter has removal efficiency about 74.3%~85.9% for SO3. Most technologies of wet flue gas desulfurization have removal efficiency of above 50% for SO3 except the empty absorption tower desulfurization and seawater desulfurization under ultra-low emission condition. Besides, the removal efficiency of wet electrostatic precipitator for SO3 can be above 50% as well, although there is still a slight gap compared with the mature cases abroad. Overall, the comprehensive removal efficiency for SO3 of the whole process environmental protection purification equipment of ultra-low emission coal-fired power plants is over 90% and the SO3 emission concentration of most units are less than 5 mg/m^3, when the sulfur content of coal is under 1.5%.
作者
李小龙
李军状
段玖祥
易玉萍
张文杰
LI Xiaolong;LI Junzhuang;DUAN Jiuxiang;YI Yuping;ZHANG Wenjie(Guodian Science and Technology Research Institute Co., Ltd., Nanjing 210046, China;Guodian Nanjing Electric Test Research Co., Ltd., Nanjing 210046, China)
出处
《中国电力》
CSCD
北大核心
2019年第10期155-161,共7页
Electric Power
基金
国家自然科学基金资助项目（41771498）
国家重点研发计划资助项目（2017YFB0603203）~~
关键词
燃煤电厂
超低排放
SO3
协同控制
排放限值
coal-fired power plant
ultra-low emission
SO3
cooperation control
emission limit
