PM_(2.5)在线监测样品采集的除湿调温系统及其性能  

Performances study on dehumidification and regulating temperature system of monitoring ambient air particulate matter mass concentrations sampling

作　　者：黄双蕾 曾志云[1] 孙凯璇[1] 朱衷榜[1] 吴代赦[1] HUANG Shuanglei ZENG Zhiyun SUN Kaixuan ZHU Zhongbang WU Daishe(College of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330029, Chin)

机构地区：[1]南昌大学资源环境与化工学院环境工程系,南昌330029

出　　处：《环境工程学报》2016年第11期6795-6800,共6页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(41363006);江西省研究生创新专项资金项目(YC2013-S024)

摘　　要：根据国家标准要求,PM_（2.5）的监测需要对采集的颗粒物在15~30℃范围内某一温度下、（50±5）%的相对湿度下进行恒重。因此,PM_（2.5）在线监测时,宜对样品进行即时除湿、调温处理。设计、制作了一套数控气体除湿调温装置,研究了影响该装置运行效果的因素,以优化系统运行的主要参数。结果表明：随着样品气在除湿调温系统内停留时间增长,其除湿量也相应增大,停留时间为27 s时除湿达到平衡;干燥气与样品气的流量比对样品气的除湿有重要影响,流量比从0.5增大到1.17时,除湿率随流量比的增大而上升,流量比为1.17时除湿率最大,达到50.97%,流量比增大到1.33以后直到2.0,随着流量比的增大除湿率反而逐渐降低;系统运行参数的优化设置,即样品气在除湿调温系统内停留时间为27s,干燥气与样品气流量比的最大值设置为1.17,通过改变干燥气与样品气的流量比来实现对除湿量的精确控制;对含湿量在63.70 g·m-3以下的样品气进行除湿调温处理都可使样品气出气的含湿量符合PM_（2.5）监测的国家标准要求,该除湿系统可满足我国PM_（2.5）日常在线监测对样品气处理的需求。The Technical Specifications for Gravimetric Measurement Method for PM_（2.5）in Ambient Air clearly state that particulate samples must achieve constant weight at specified temperature（ 15—30 ℃） and relative humidity（ RH,45% —55%） ranges. Thus,an immediate process of dehumidification and tempering treatment was significant in the PM_（2.5）online monitoring field. A set of dehumidification and regulating temperature system of monitoring ambient air particulate matter mass concentrations sampling was developed,aimed at reducing water vapor interference. A series of experiments was conducted to identify the influencing factors and to optimize operating parameters. The multivariate experiments highlighted that dehumidification was more efficient with longer retention time of sample gas,while the exchange of dry gas and sample gas got a balance at retention time of 27 s. The flow ratios of dry gas and sample gas greatly influenced dehumidification： when flow ratio increased from 0. 5 to 1. 17,the dehumidification rate increased accordingly（ maximum dehumidification 50. 97%）; dehumidifying also showed a gradual decrease when the flow ratio increased from 1. 33 to 2. 0. The optimization study successfully treated ambient air and experimental air,with maximum humidity of 63. 79 g·m-3following optimized sample retention time of 27 s and maximum flow ratio of 1. 17.

关 键 词：除湿 调温 空气颗粒物 在线监测 

分 类 号：X851[环境科学与工程—环境工程]