Simulation of three-stage operating temperature for supersaturation water-based condensational growth tube
Simulation of three-stage operating temperature for supersaturation water-based condensational growth tube作者机构:Key Laboratory of Environmental Optics and TechnologyAnhui Institute of Optics and Fine MechanicsChinese Academy of SciencesHefei 230031China University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Regional Atmospheric EnvironmentInstitute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of SciencesBeijing 100049China
出 版 物:《Journal of Environmental Sciences》 (环境科学学报(英文版))
年 卷 期:2020年第32卷第4期
页 面:275-285页
核心收录:
学科分类:0830[工学-环境科学与工程(可授工学、理学、农学学位)] 07[理学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学]
基 金:supported by Natural Science Foundation of China(No.91544218) the National Key Research and Development Program of China(No.2016YFC0201001) the Science and Technological Fund of Anhui Province for Outstanding Youth(1808085J19) the Science and Technological Fund of Anhui Province(1908085MD114) The CASHIPS Director’s Fund,Grant NO.YZJJ2019QN1
主 题:Operating temperature Supersaturation profile Flow rate Minimum activation size Temperature difference
摘 要:In order to realize accurate dynamic control of supersaturation and to study condensation growth characteristics of nanoparticles through different levels of super saturation,a series of parametric analyses and systematic comparisons between two-stage and three-stage operating temperature designs were simulated with COMSOL Multiphysics.The simulation results showed that the three-stage operating temperature did not change peak supersaturation compared with two operating temperatures,and the three-stage operating temperature was superior in decreasing the amount of water vapor and the temperature,thus lowering particle loss and variation in detection and collection.The peak supersaturation level increased by 0.3 as the flow rate increased from 0.6 to 2.0 L/min,but the supersaturation peak moved from 0.0027 z0 to 0.08 z0(i.e.,the growth time and the final size decreased by 40%).Peak supersaturation increased as the temperature difference increased or the temperature difference window was shifting left,and minimum activation size decreased.Shifting the 70℃temperature difference window from 9℃,79℃-1℃,71℃for the condenser and initiator temperatures resulted in peak supersaturation in the centerline being above 5.8,and the activation size changed as low as 1 nm.Experiments with flow rates varying by a factor of 2.5(from 0.6 to 1.5 L/min)resulted in a final size decrease of 43%(from 3.2 to 1.8μm),and experimental results of outlet particle size distributions were equivalent with theoretical analysis as the operating temperature was changed.