高浓度的大气污染同样影响着室内的空气质量。随着人们对细颗粒物污染的关注度的提升，空气净化设备大量涌现。计算流体力学可以通过有限元分析，应用流体力学基本方程计算流场中的温度场、风场、气压场、浓度场等，已有用于气体污染问题研究的案例且日趋成熟。本文使用计算流体力学软件ANSYS FLUENT内置的能量方程、k-ε方程和组分传输模型的组合对空气净化设备运行时的室内颗粒物浓度场变化进行计算，分析空气净化设备在不同状态下的净化效果。结果显示，净化器出风口质量流速和风速决定了其净化效果；低风速状态下，空气净化主要靠颗粒物扩散来实现，高风速状态下，则依靠湍流混合机制，可以使净化后的清洁气体与待净化迅速混合，降低空间的平均颗粒物浓度；在质量流速恒定的情况下，提升风速获得的效率增益大于扩大出风口面积，增大出风口面积不利于净化效率的提升，但可以降低浓度低值区的最低值，适合小范围净化；在小室内净化器安装的水平位置对净化效率影响很小，但合适的垂直高度可使人员活跃区域的空气保持较低的颗粒物浓度。

The quality of the atmosphere has great impact on the indoor air quality. Nowadays, the sale volume of air cleaners enlarges dramatically as people are paying more and more attention on the fine particulate matter pollution. Computational fluid dynamics is a finite element analysis tool applied to compute the field of temperature, wind, pressure and concentration, etc. already being used in studying air pollution. In this paper, we turn on the energy equation and viscous model（standard k-epsilon model）as well as species transport model of ANSYS FLUENT to compute the concentration field of certain room equipped with an air cleaner. It turns out that the purification efficiency is largely depend on the mass flow rate and the wind speed of air cleaner. The concentration of particulate matter declines mostly through diffusion in low wind speed and turbulence in high wind speed. To certain mass flow rate, the increasing of wind speed counts more in the improvement of purification efficiency than that of area of outlet. The position of air cleaner has poor effect on the purification efficiency. However, proper height of air cleaner should be set to minimize the concentration of particulate matter on the level of 1.0 to 1.5m, of which air people breathe often.