基于实测的烟气“消白”工程环境效益研究

Study on Environmental Benefits of Wet Plume Treatment Project Based on Actual Measurements

为研究烟气“消白”工程的环境效益,采用RJ-SO3-M型便携式SO3分析仪对河北邯郸某电厂600 MW机组烟气“消白”工程进行了现场测试,收集了烟气“消白”工程实施前后相近运行负荷、相近煤质、相同时间段的烟尘、SO2、NOx的连续监测数据。研究结果表明,烟气“消白”工程中的冷却降温对FGD、WESP脱除SO3的影响很小,烟气温降与FGD、WESP、FGD+WESP对SO3的脱除效率之间没有相关性,温降为0℃、2.9℃、3.9℃和5.8℃的4种工况条件下,F G D+W E S P对S O 3总的脱除效率介于75.6%~81.9%,平均为78.9%。烟气“消白”工程中,烟气降温有利于WESP对颗粒物的脱除,烟尘排放质量浓度约下降0.5 mg/m3,SO2和NOx排放浓度基本无变化。烟气中SO3的脱除主要取决于FGD和WESP,而与烟气是否冷却降温基本无关。烟气冷却降温不是减少污染物排放的有效方法。

In order to evaluate the environmental benefits, onsite measurements were retrieved by using the RJ-SO3-M portable SO3 analyzer in the wet plume treatment project of a 600 MW power unit in Handan, Hebei Province. The monitoring data of dust, SO2 and NOx before and after the wet plume treatment project were continuously collected under the conditions of similar operating load,coal quality and time period of operations. The results show that the flue gas cooling has very limited effects on the removal of SO3 by FGD and WESP. In addition, there is no correlation between flue gas temperature drop and SO3 removal efficiency of FGD,WESP and FGD + WESP. The total removal efficiency of SO3 by FGD + WESP is between 75.6% and 81.9%, with the average of 78.9% under the conditions of the temperature drop by 0 °C, 2.9 °C, 3.9 °C and 5.8 °C respectively. The temperature drop of flue gas in the wet plume treatment project is beneficial to the removal of particulate matter by WESP. For instance, the mass concentration of dust emission has decreased by 0.5 mg/m3, while the concentration of SO2 and NOx emission remains almost unchanged. The removal of SO3 in flue gas mainly depends on FGD and WESP, but has almost nothing to do with whether the flue gas has been cooled down. Therefore cooling down the flue gas temperatures turns out not an effective way to reduce the emission of pollutants.