固定源可凝结颗粒物监测技术研究

Researches on the Monitoring Technology of Condensable Particulate Matter Emitted by Stationary Sources

应用CFD软件模拟固定源排放的湿烟气和CPM(Condensable Particulate Matter,可凝结颗粒物)在不同风速下的扩散过程,表明CPM与湿烟气中的水分在烟囱出口周边大气中的扩散分布情况基本一致,有着类似的形成过程.温度是决定CPM和水分凝结的关键因素,CPM测试数据应标明样品采集时的冷凝温度,(0±1)℃是最佳冷凝温度,可获得较高的捕集效率.参考《排放管道中可凝结性微粒检测方法》(EPA Method 202)和《固定污染源废气低浓度颗粒物的测定重量法》(HJ 836—2017),设计并制作了适于国内污染源监测实际的CPM采样装置.经现场实际测定,该装置可以较好地应用于我国污染源监测实际.相较稀释通道法,干冲击瓶法更适合成为污染源监测的标准分析方法.此外,讨论了CPM测定中样品回收、全程序空白值偏高等需注意的问题.

CFD software was used to simulate the diffusion process of wet flue gas and CPM(Condensable Particulate Matter)emitted from fixed sources at different wind speeds.The results showed that the diffusion distribution of CPM and moisture in wet flue gas in the atmosphere around the chimney outlet was basically the same and had similar formation process.Temperature was the key factor during the test of CPM,and the test data should be indicated the condensation temperature when samples were collected.The proper condensation temperature was(0±1)℃which could achieve higher capture efficiency.Refer to Test Method for Condensible Particulates in Discharge Pipe EPA Method 202 and Determination Gravimetric Method for Low Concentration Particulates in Exhaust Gas from Stationary Sources HJ 836—2017,a CPM sampling device suitable for domestic pollution monitoring was designed and manufactured.Successful test activities showed that the device can be used in monitoring stationary sources in China.Compared with the dilution method,dry impact bottle method was more suitable for the standard analysis method of stationary monitoring.In addition,the problems of sample recovery and the abnormal high blank value of the whole procedure test blank in spots were discussed in paper.