摘要
目的:进一步降低冷凝粒子计数器检测颗粒的粒径下限。方法:基于颗粒冷凝生长技术,在已有的三段式颗粒生长装置设计上,新增一个“采样段”;通过调整该采样段的温度和流速,达到降低检测颗粒粒径下限的目的。结果:实验结果表明:在四段式颗粒生长装置中,当采样段的温度从30℃降低至5℃时,颗粒的中值粒径从3.28μm增加至3.79μm;当采样段流速从0.2 L/min降低至0.1 L/min时,颗粒中值粒径从3.05μm增加至4.07μm。数值模拟结果表明:在四段式颗粒生长装置中,当采样段温度从30℃降低至5℃时,系统过饱和峰值增加约0.3;检测颗粒的粒径下限从1.72 nm降低至1.56 nm。当采样段流速从0.21 L/min降低至0.03 L/min时,系统过饱和峰值增加约0.2;检测颗粒的粒径下限从1.69 nm降低至1.59 nm。结论:新的四段式设计,通过降低采样段的温度及流速,进一步提升了系统的过饱和峰值、增加了颗粒中值粒径,降低了检测颗粒的粒径下限。
Aims:This paper aims to further reduce the lower detection limit of particle size in condensation particle counters.Methods:Based on the particle condensation growth technology,a“sampler”was integrated into the existing three-stage particle growth device design.By precisely adjusting the temperature and flow velocity within this stage,the lower detection limit of particle size could be effectively reduced.Results:The experimental results showed that in a four-stage particle growth system,when the temperature of the sampler was decreased from 30℃to 5℃,the median particle size increased from 3.28μm to 3.79μm.When the flow rate in the sampler was reduced from 0.2 L/min to 0.1 L/min,the median particle size increased from 3.05μm to 4.07μm.Numerical simulations of the four-stage particle growth device revealed that the reducing of the sampler temperature from 30℃to 5℃increased the system's supersaturation peak value by approximately 0.3,thereby lowering the particle size detection limit from 1.72 nm to 1.56 nm.Similarly,the decreasing of the sampler flow rate from 0.21 L/min to 0.03 L/min enhanced the supersaturation peak by 0.2 and reduced the detection limit from 1.69 nm to 1.59 nm.Conclusions:Reducing the temperature and flow rate in the sampler further enhances the system's supersaturation peak,increases the median particle size,and lowers the detection lower limit for particle size.
作者
陈曦
李旭娟
于明州
CHEN Xi;LI Xujuan;YU Mingzhou(College of Mechanical and Electrical Engineering,China Jiliang University,Hangzhou 310018,China;College of Metrology Measurement and Instrument,China Jiliang University,Hangzhou 310018,China;College of Sciences,China Jiliang University,Hangzhou 310018,China)
出处
《中国计量大学学报》
2025年第1期17-25,共9页
Journal of China University of Metrology
基金
国家自然科学基金项目(No.11872353)
浙江省自然科学基金项目(No.LZ22A020004)。
关键词
冷凝粒子计数器
颗粒生长
颗粒粒径分布
过饱和度
condensation particle counter
particle growth
particle size distribution
supersaturation
