在用车排放颗粒测量仪器标定及实验研究

Calibration and experimental research of in-use vehicle particulate emission measurement instruments

目的:在用车尾气排放颗粒物数目含量检测技术和设备国产化。方法:基于凝结核增长计数原理,采用自稀释结构,并调整温度设置,研发了纳米级细颗粒物计数仪器,并在洁净间进行了标定实验,同时,基于标定完成的自研CPC仪器对在用车排放尾气颗粒物数目含量进行了实地测量。结果:在使用自稀释结构,采样温度为6~50℃下,自研仪器的D50达到了9.2 nm,满足机动车D50为23±1 nm的检测要求,仪器瞬态响应误差为9.53%,检测范围在0~5×10^(4)个/mL,满足仪器误差指标。此外,针对在用车排放尾气的实地测量结果表明,自研CPC具有较好的辨识能力,可以准确地捕捉到不同量级的颗粒物数目含量变化趋势,且自研CPC与TSI CPC的峰值相对误差变化均低于10%。结论:研制的仪器达到机动车尾气检测标准,且仪器检测范围内一致性较高。

Aims:This paper aims to achieve the local technology and equipment for detecting the concentrations and particles in vehicle exhaust emissions.Methods:This study developed a nanoscale fine particle counting instrument based on the principle of nucleation growth counting.Adopting a self dilution structure and adjusting the temperature setting,calibration experiments were conducted in a controlled clean room environment.Results:With the use of a self-dilution structure and sampling temperature of 6~50℃,the D 50 of the instrument reached 9.2 nm,meeting the detection requirements of 23±1 nm for motor vehicles.The transient response error of the instrument was 9.53%,the detection range was from 0 to 5×10^(4) particles/mL,thus meeting the instrument error index.The on-site measurements of exhaust emissions from in-use vehicles showed that the developed condensation particle counter(CPC)accurately identified the changes in particle concentration across different magnitudes.Moreover,both the developed CPC and the TSI CPC exhibited peak relative error changes of less than 10%.Conclusions:The developed instrument meets the standard of motor vehicle exhaust testing with high consistency and detection ranges.