The mechanism of low-speed steady substitution flow to clean the indoor particulate matter
LIN Guan-ming1, REN Zhen-hai2, SONG Jian-li3
1. State Joint Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Science and Engineering, Peking University, Beijing 100871, China; 2. Chinese Research Academy of Environmental Sciences, Beijing 100012, China; 3. Shijiazhuang Aoxiang Pharmaceutical Engineering Co., Ltd., Shijiazhuang 050031, China
Abstract：The mechanism of the indoor particulate matter's transportation and diffusion was discussed. Using the spatial and temporal scale analysis, the particulate matter's flux can be artificially separated into four parts:the advection and slippage in the slowly varying macro mean motion δ-scale, the turbulent diffusion in the rapidly varying micro turbulence motion η-scale and the Brown diffusion in the dramatically varying molecular motion λ-scale. Correspondingly, the flux equations in the ensemble average format and model computing format were concluded. Following the equations, the methods to increase the purification efficiency were lowering the indoor air speed and its turbulence intensity gradient. The flow fields was numerically simulated in a typical room with the low-speed steady substitution flow system installed and in a normal room with both air inlet and outlet on the roof. The particulate matter's number concentration was measured in two rooms with different air inlet and outlet positions. The results showed that the ways to improve the purification efficiency and to decrease the energy cost were:1) keeping a weak positive pressure; 2) setting the ceiling corner line air inlet and baseboard corner line air outlet layout; 3) lowering the air speed and turbulence gradient.
林官明, 任阵海, 宋建立. 室内颗粒物的稳态置换流净化机制[J]. 中国环境科学, 2018, 38(1): 97-102.
LIN Guan-ming, REN Zhen-hai, SONG Jian-li. The mechanism of low-speed steady substitution flow to clean the indoor particulate matter. CHINA ENVIRONMENTAL SCIENCECE, 2018, 38(1): 97-102.
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