Engineering College, Guangdong Ocean University, Zhanjiang 524088, People's Republic of China.
J R Soc Interface. 2012 Dec 7;9(77):3184-95. doi: 10.1098/rsif.2012.0439. Epub 2012 Jul 18.
There has been increasing interest in the use of upper-room ultraviolet germicidal irradiation (UVGI) because of its proven effectiveness in disinfecting airborne pathogens. An improved drift flux mathematical model is developed for optimizing the design of indoor upper-room UVGI systems by predicting the distribution and inactivation of bioaerosols in a ventilation room equipped with a UVGI system. The model takes into account several bacteria removal mechanisms such as convection, turbulent diffusion, deposition and UV inactivation. Before applying the model, the natural die-off rate and susceptibility constants of bioaerosols were measured experimentally. Two bacteria aerosols, Escherichia coli and Serratia marcescens, were tested for this purpose. It was found out that the general decay trend of the bioaerosol concentration predicted by the numerical model agrees well with the experimental measurements. The modelling results agree better with experimental observations for the case when the UVGI inactivation mechanism dominates at the upper-room region than for the case without UVGI. The numerical results also illustrate that the spatial distribution of airborne bacteria was influenced by both air-flow pattern and irradiance distribution. In addition to predicting the local variation of concentration, the model assesses the overall performance of an upper-room UVGI system. This model has great potential for optimizing the design of indoor an upper-room UVGI systems.
由于上空气流紫外线杀菌（UVGI）在消毒空气传播病原体方面的有效性已得到证实，因此人们对上空气流紫外线杀菌的兴趣日益增加。通过预测装有 UVGI 系统的通风室中生物气溶胶的分布和失活情况，开发了一种改进的漂移通量数学模型，以优化室内上空气流 UVGI 系统的设计。该模型考虑了几种细菌去除机制，例如对流、湍流扩散、沉积和 UV 失活。在应用模型之前，通过实验测量了自然衰减率和生物气溶胶的敏感性常数。为此目的测试了两种细菌气溶胶，即大肠杆菌和粘质沙雷氏菌。结果表明，数值模型预测的生物气溶胶浓度的总体衰减趋势与实验测量结果吻合较好。与没有 UVGI 的情况相比，当 UVGI 失活机制在上气室区域占主导地位时，模型结果与实验观察结果更为一致。数值结果还表明，空气传播细菌的空间分布受气流模式和辐照度分布的影响。除了预测浓度的局部变化外，该模型还评估了上空气流 UVGI 系统的整体性能。该模型对于优化室内上空气流 UVGI 系统的设计具有很大的潜力。
