超低排放煤电机组主要大气污染物排放分析

Emission analysis of main air pollutants from ultra-low emission coal-fired power units

以30家发电企业64台已实施超低排放改造的煤电机组为研究对象,调查研究了超低排放燃煤机组主要大气污染物(颗粒物、SO_(2)、NO_(x))年均排放质量浓度、单位发电量排放强度、达标排放率以及环保设施运行情况,多维度对比分析了各机组环保水平。研究结果显示:参与调查机组的颗粒物、SO_(2)、NO_(x)年度达标排放率分别为99.987%、99.978%、99.927%,能够稳定实现超低排放;SO_(2)排放质量浓度均值仅达到排放限值的48.02%,颗粒物排放质量浓度均值仅达到排放限值的29.00%,表明SO_(2)、颗粒物排放质量浓度限值还有一定提升空间;启停机时段颗粒物、NO_(x)、SO_(2)超标排放时长在各类污染物超标时长中占比分别为60%、63%、35%,表明启停机时段各类污染物超标时间较长,通过技术措施减缓启停机对环保设施的影响是下步工作重点;各容量等级机组超低排放技术装备水平基本一致的前提下,按机组容量划分时,颗粒物、SO_(2)、NO_(x)的实际排放强度较为接近,受制于机组整体负荷率较低,大容量机组的清洁生产水平未完全体现。

By taking 64 coal-fired power units in 30 power generation enterprises that have implemented ultra-low emission transformation as the research objects,the average annual emission mass concentration of air pollutants(particulate matters,SO_(2),NO_(x)) of ultra-low emission coal-fired units,emission intensity per unit power generation,emission rate up to standard and the operation of environmental protection facilities were investigated,and the environmental protection level of each unit was compared in multiple dimensions.The research results show that,the annual emission compliance rates of particulate matters,SO_(2),and NO_(x) of the surveyed units are 99.987%,99.978%,and 99.927%,respectively,which can realize ultra-low emissions stably.The average emission mass concentration of SO_(2) only reaches 48.02%of the emission limit,and that of particulate matters only reaches 29.00%of the emission limit,indicating that there is still some potential for improvement of SO_(2) and particulate matters emission limit.The over standard emission time of particulate matters,NO_(x) and SO_(2) during the unit startup and shutdown accounts for 60%,63%and 35%of the sum of all pollutants respectively,indicating that the overtandard emission time of various pollutants during startup and shutdown is relatively long.Mitigating the impact of startup and shutdown on environmental protection facilities through technical measures is the focus of the future work.On the premise that the level of ultra-low emission technical equipment of units at all capacity levels is basically the same,when divided according to the unit capacity,the actual emission intensity of particulate matters,SO_(2) and NO_(x) is relatively close,subjected to the low overall load rate of the unit,the clean production level of large capacity units is not fully reflected.