民用固体燃料燃烧大气污染物排放稀释采样器的研制与应用

Development and application of a dilution sampler for measuring air pollutants from residential solid fuel combustion

为研究民用固体燃料燃烧大气污染物的排放特征,研制开发了一套紧凑型稀释采样器,主要由烟气进气部分、稀释空气部分、稀释混合部分及采样部分四部分组成.结果表明,该采样器可测量排放的一次PM2.5、CO2、CO、SO2、NOx等气态污染物排放浓度,并可根据碳平衡法获得各污染物的排放因子.稀释采样器的稀释比在20∶1~30∶1范围内,样气在稀释器内的停留时间为10 s.性能评价表明,稀释器气密性良好,稀释空气中颗粒物浓度低于3μg·m^-3,气流混合均匀,理论稀释比与实际稀释比的偏差均小于2%,细颗粒在采样器内的损失小.利用稀释器测试了两种典型民用炉具和煤种组合的大气污染物的排放,发现高效反烧炉与无烟煤球组合的PM2.5的排放因子要显著低于传统正烧炉与烟煤组合,且前者CO和NOx的排放因子也要低于后者,两种CO2排放因子相当.

A compact dilution sampler was developed to study air pollutants emitted from residential solid fuel combustion, which included flue gas intake part, dilution air part, dilution mixing part and sampling part. The sampler could measure the concentrations of primary PM2.5 and CO2, CO, SO2 and NOx. Furtherly, emission factors of those pollutants were determined based on carbon balance method. The dilution ratio of the sample ranges from 20∶1 to 30∶1, and the residence time is no less than 10 seconds. Performance assessment showed excellent air tightness and extremely low fine particle concentration in the dilution air(less than 3 μg·m^-3). Sampling gas and dilution air was well mixed, and fine particle loss in the sampler was acceptable. Bias between theoretical ratios and actual dilution ratios was less than 2%. The sampler has been applied to measure air pollutants emitted from two typical combinations of residential coal-stoves and coals. The results showed that PM2.5 emission factors for the backfire stove with anthracite briquette burning were significantly less than those of traditional stove with bituminous chunk coal burning. Emission factors of CO and NOx for the former stove were also lower than the latter one. CO2 emission factors for both were comparable.