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[1] Gao Naiping, Niu Jianlei, Lidia Morawska,. Distribution characteristics of respiratory aerosolsin enclosed environments [J]. Journal of Southeast University (English Edition), 2010, 26 (2): 232-237. [doi:10.3969/j.issn.1003-7985.2010.02.019]
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Distribution characteristics of respiratory aerosolsin enclosed environments()
人体呼出气溶胶在封闭环境中的分布特性
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Journal of Southeast University (English Edition)[ISSN:1003-7985/CN:32-1325/N]

Volumn:
26
Issue:
2010 2
Page:
232-237
Research Field:
Energy and Power Engineering
Publishing date:
2010-06-30

Info

Title:
Distribution characteristics of respiratory aerosolsin enclosed environments
人体呼出气溶胶在封闭环境中的分布特性
Author(s):
Gao Naiping1;  Niu Jianlei2;  Lidia Morawska3
1College of Mechanical Engineering, Tongji University, Shanghai 200092, China
2Department of Building Services Engineering, the Hong Kong Polytechnic University, Hong Kong, China
3School of Physical and Chemical Sciences, Queensland University of Technology, Queensland, Australia
高乃平1;  牛建磊2;  Lidia Morawska3
1同济大学机械工程学院, 上海 200092; 2香港理工大学屋宇设备工程学系, 中国香港; 3School of Physical and Chemical Sciences, Queensland University of Technology, Queensland, Australia
Keywords:
respiratory droplets;  displacement ventilation;  under-floor air distribution(UFAD);  transmission;  airborne disease
呼吸道飞沫;  置换送风;  地板送风;  传输;  空气传播
PACS:
TU834
DOI:
10.3969/j.issn.1003-7985.2010.02.019
Abstract:
This paper studies the spatial concentration distribution and temporal evolution of exhaled and sneezed/coughed droplets within the range of 1.0 to 10.0 μm in an office room with three air distribution methods, including mixing ventilation(MV), displacement ventilation(DV), and under-floor air distribution(UFAD).The simulation results indicate that exhaled droplets with diameters up to 10.0 μm from normal respiration process are uniformly distributed in MV.However, they become trapped at the breathing height by thermal stratifications in DV and UFAD, resulting in a high droplet concentration and an increased exposure risk to other occupants.Sneezed/coughed droplets are more slowly diluted in DV/UFAD than in MV.Low air speed in the breathing zone in DV/UFAD can lead to prolonged human exposure to droplets in the breathing zone.
研究了1.0~10.0 μm的呼吸道颗粒物在混合送风、置换送风和地板送风的办公室环境中的浓度空间分布和瞬态演变规律.仿真结果表明:小于10.0 μm的飞沫在混合送风的房间内几乎是均匀分布的.然而, 在置换送风和地板送风中, 垂直温度梯度使得小于10.0 μm的飞沫在人体呼吸区高度聚集, 导致一个较高的浓度水平, 因此室内人员被感染的概率比较高.由咳嗽或者打喷嚏产生的飞沫在置换和地板送风中的稀释(浓度衰减)比在混合送风中慢, 这是因为置换和地板送风中人体呼吸区的风速比较小, 飞沫在此聚集, 不易被气流携带排出室内空间.

References:

[1] Li Y G, Leung G M, Tang J W, et al.Role of ventilation in airborne transmission of infectious agents in the built environment—a multidisciplinary systematic review [J].Indoor Air, 2007, 17(1):2-18.
[2] Public Health Service Centers for Disease Control and Prevention.Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care facilities [R].Atlanta, GA, USA:Public Health Service Centers for Disease Control and Prevention, US Department of Health and Human Services, 1994.
[3] Gao N P, Niu J L.Modeling particle dispersion and deposition in indoor environments [J].Atmospheric Environment, 2007, 41(18):3862-3876.
[4] Qian H, Li Y, Nielsen P V, et al.Dispersion of exhaled droplet nuclei in a two-bed hospital ward with three different ventilation systems [J].Indoor Air, 2006, 16(3):111-128.
[5] Zhu S W, Kato S, Yang J H.Study of transport characteristics of saliva droplets produced by coughing in a calm indoor environment [J].Building and Environment, 2006, 41(12):1691-1702.
[6] Lai A C K, Nazaroff W W.Modeling indoor particle deposition from turbulent flow onto smooth surfaces [J].Journal of Aerosol Science, 2000, 31(4):463-476.
[7] Friberg B, Friberg S, Burman L G, et al.Inefficiency of upward displacement operating theater ventilation [J].Journal of Hospital Infection, 1996, 33(4):263-272.
[8] Abadie M O, Liman K.Numerical evaluation of the particle pollutant homogeneity and mixing time in a ventilated room [J].Building and Environment, 2007, 42(11):3848-3854.
[9] Gadgil A J, Lobscheid C, Adadie M O, et al.Indoor pollutant mixing time in an isothermal closed room:an investigation using CFD [J].Atmospheric Environment, 2003, 37(39/40):5577-5586.

Memo

Memo:
Biography: Gao Naiping(1978—), male, doctor, associate professor, gaonaiping@tongji.edu.cn.
Foundation items: The National Natural Science Foundation of China(No.50808133), the Dean’s Reserve of Faculty of Construction and Land Use at the Hong Kong Polytechnic University.
Citation: Gao Naiping, Niu Jianlei, Lidia Morawska.Distribution characteristics of respiratory aerosols in enclosed environments[J].Journal of Southeast University(English Edition), 2010, 26(2):232-237.
Last Update: 2010-06-20