Abstract. Oxidation flow reactors (OFRs) are frequently used to study the formation and evolution of secondary aerosol (SA) in the atmosphere and have become valuable tools for improving the accuracy of model simulations and for depicting and accelerating realistic atmospheric chemistry. Driven by rapid development of OFR techniques and the increasing appreciation of their wide application, we designed a new all-Teflon reactor, the Particle Formation Accelerator (PFA), and characterized it in the laboratory and with ambient air. A series of simulations and experiments were performed to characterize: (1) flow profiles in the reactor using computational fluid dynamics (CFD) simulations, (2) the UV intensity distribution in the reactor and the influence of it and varying O₃ concentration and relative humidity (RH) on the resulting equivalent OH exposure (OH_exp), (3) transmission efficiencies for gases and particles, (4) residence time distributions (RTD) for gases and particles using both computational simulations and experimental verification, (5) the production yield of secondary organic aerosol (SOA) from oxidation of α-pinene and m-xylene, (6) the effect of seed particles on resulting SA concentration, and (7) SA production from ambient air in Riverside, CA, U.S. The reactor response and characteristics are compared with those of a smog chamber (Caltech) and of other oxidation flow reactors (the Toronto Photo-Oxidation Tube (TPOT), the Caltech Photooxidation Flow Tube (CPOT), and quartz and aluminum versions of Potential Aerosol Mass reactors (PAMs)). Our studies show that: (1) OH_exp can be varied over a range comparable to that of other OFRs, (2) particle transmission efficiency is over 75 % in the size range from 50 to 200 nm, after minimizing static charge on the Teflon surfaces, (3) the penetration efficiencies of CO₂ and SO₂ are 0.90 ± 0.02 and 0.76 ± 0.04, respectively, the latter of which is comparable to estimates for LVOCs, (4) a near laminar flow profile is expected based on CFD simulations and suggested by the RTD experiment results, (5) m-xylene SOA and α-pinene SOA yields were 0.22 and 0.37, respectively, at about 3 × 10¹¹ molec. cm⁻³ s OH exposure, (6) the mass ratio of seed particles to precursor gas has a significant effect on the amount of SOA formed, and (7) during measurements of SA production when sampling ambient air in Riverside, the mass concentration of SA formed in the reactor was an average of 1.8 times that of the ambient aerosol at the same time.

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新型OFR的设计与表征：粒子形成促进剂（PFA）

摘要。氧化流反应器（OFR）经常用于研究大气中二次气溶胶（SA）的形成和演变，并已成为提高模型模拟的准确性以及描绘和加速现实的大气化学作用的有价值的工具。在OFR技术的快速发展和对它们广泛应用的日益赞赏的驱使下，我们设计了一种新型的全铁氟龙反应器颗粒形成促进剂（PFA），并在实验室和环境空气中对其进行了表征。进行了一系列模拟和实验以表征：（1）使用计算流体力学（CFD）模拟的反应器中的流量分布；（2）反应器中的UV强度分布及其影响和O _3的变化（3）气体和颗粒的传输效率，（4）气体和颗粒的停留时间分布（RTD），同时使用计算模拟和实验验证，得出的当量OH暴露浓度（RH _exp）的浓度和相对湿度（RH），（4） 5）从α蒎烯和氧化二次有机气溶胶的产率（SOA）米-二甲苯，（6）种子颗粒对所得SA浓度的影响，以及（7）美国加利福尼亚州里弗赛德市的环境空气中SA的产生。将反应器的响应和特性与烟雾室（Caltech）和其他氧化流反应器（多伦多光氧化管（TPOT），加州理工学院光氧化流管（CPOT）以及潜在气溶胶质量反应器（PAM）的石英和铝版本）。我们的研究表明：（1）OH _exp可以在与其他OFR相当的范围内变化；（2）在最小化聚四氟乙烯上的静电荷后，粒子传输效率在50至200 nm的尺寸范围内超过75％表面，（3）CO ₂和SO ₂的渗透效率分别为0.90±0.02和0.76±0.04，其中后者是可比估计LVOCs，（4）的近层流简档是基于CFD模拟预期的和由RTD实验结果表明，（5）米二甲苯在大约3×10 ¹¹ 摩尔下，SOA和α- pine烯的SOA产率分别为0.22和0.37 。cm ^-3  s OH暴露，（6）种子颗粒与前驱物气体的质量比对SOA形成量有显着影响，（7）在测量河滨环境空气中的SA产量期间，SA的质量浓度同时在反应器中形成的SA平均是周围气溶胶的1.8倍。