火电厂排放烟气白雾治理新方案及节能分析

  目的]  烟气经过湿法脱硫后，若不经过处理直接排放，经常会发生白雾现象，造成“视觉污染”。  方法]  对湿法脱硫排放烟气产生的白雾现象原理进行理论研究，通过烟气热力特性曲线方程，采用“湿度-温度”图，分析了白雾产生的热力过程，提出了先降温除湿再加热的白雾治理新方案。结合某超超临界1 000 MW等级燃煤机组，对新方案的节能效益进行计算。  结果]  研究成果表明:在一定的工程边界条件及设计原则下，新方案饱和烟气的加热功率要比常规方案小10.511 6 MW，在考虑烟气余热用于凝结水系统和不考虑烟气余热用于凝结水系统两种情况下，机组效率分别增加0.231%、0.164%。  结论]  采用白雾治理新方案，可以达到同样的白雾治理效果，获得更好的节能效益。

New Scheme and Energy Saving Analysis of Flue Gas White Fog Treatment in Thermal Power Plant

  Introduction]  The white fog is often appeared and causes "visual pollution" if the exhaust gas after wet desulphurization is not controlled.  Method]  The white fog phenomenon from the exhaust gas after wet desulphurization was studied theoretically, and the thermal process of the white fog was analyzed with the help of the flue gas thermal characteristic curve equation and "temperature-humidity" chart, so a new scheme of the white fog treatment for cooling, dehumidification and heating was presented. Combined with a typical 1 000 MW ultra-supercritical coal-fired unit, the energy-saving effects of the new scheme were calculated.  Results]  The results show that: based on certain boundary conditions of the project and design principles, the saturated gas heating power of the new scheme is decreased by 10.511 6 MW, in two cases that the flue gas waste heat is used to heating condensate water or is not used to heating condensate water, the unit efficiency is increased by 0.231% and 0.164% than the general scheme respectively.  Conclusion]  A new scheme of the white fog treatment can achieve the same effect of the white fog treatment and that has better energy-saving effects.