One important area where the development of economically viable products can improve the quality and comfort of human existence is natural ventilation inside a building. Despite the wide distribution of air pollutant ...One important area where the development of economically viable products can improve the quality and comfort of human existence is natural ventilation inside a building. Despite the wide distribution of air pollutant sources, the concentration of indoor pollutants may be the dominant risk factor in relation to personal exposure, as most people spend an average of 87% and 6% of their time within enclosed rooms and vehicles, respectively. Under these circumstances, wind driven rotating ventilators, which use natural energy and are cheap to manufacture, install and maintain, can become very effective non-polluting means of alleviating the problems within enclosed spaces. The author has been pioneering design and performance studies of environment friendly products such as the rooftop ventilator for over a decade at the University of New South Wales in Australia. The purpose of this paper is to detail the basic working principles of this ventilator and the series of detailed experimental and numerical investigations that has been performed in the optimization of the rooftop ventilator in terms of performance with higher air mass extraction rate and improved safety in operation has been achieved. Findings from these studies have been incorporated in the design of ventilators that are now commercially produced and marketed throughout the world by CSR Edmonds Pry Ltd of Australia. The conduct and outcomes of these works form the basis of this keynote paper.展开更多
The effects of supply temperature and vertical location of inlet air on particle dispersion in a displacement ventilated （DV） room were numerically modeled with validation by experimental data from the literature. T...The effects of supply temperature and vertical location of inlet air on particle dispersion in a displacement ventilated （DV） room were numerically modeled with validation by experimental data from the literature. The results indicate that the temperature and vertical location of inlet supply air did not greatly affect the air distribution in the upper parts of a DV room, but could significantly influence the airflow pattern in the lower parts of the room, thus affecting the indoor air quality with contaminant sources located at the lower level, such as particles from working activities in an office. The numerical results also show that the inlet location would slightly influence the relative ventilation efficiency for the same air supply volume, but particle concentration in the breathing zone would be slightly lower with a low horizontal wall slot than a rectangular diffuser. Comparison of the results for two different supply temperatures in a DV room shows that, although lower supply temperature means less incoming air volume, since the indoor flow is mainly driven by buoyancy, lower supply temperature air could more efficiently remove passive sources （such as particles released from work activities in an office）. However, in the breathing zone it gives higher concentration as compared to higher supply air temperature. To obtain good indoor air quality, low supply air temperature should be avoided because concentration in the breathing zone has a stronger and more direct impact on human health.展开更多
文摘One important area where the development of economically viable products can improve the quality and comfort of human existence is natural ventilation inside a building. Despite the wide distribution of air pollutant sources, the concentration of indoor pollutants may be the dominant risk factor in relation to personal exposure, as most people spend an average of 87% and 6% of their time within enclosed rooms and vehicles, respectively. Under these circumstances, wind driven rotating ventilators, which use natural energy and are cheap to manufacture, install and maintain, can become very effective non-polluting means of alleviating the problems within enclosed spaces. The author has been pioneering design and performance studies of environment friendly products such as the rooftop ventilator for over a decade at the University of New South Wales in Australia. The purpose of this paper is to detail the basic working principles of this ventilator and the series of detailed experimental and numerical investigations that has been performed in the optimization of the rooftop ventilator in terms of performance with higher air mass extraction rate and improved safety in operation has been achieved. Findings from these studies have been incorporated in the design of ventilators that are now commercially produced and marketed throughout the world by CSR Edmonds Pry Ltd of Australia. The conduct and outcomes of these works form the basis of this keynote paper.
基金supported by the National Natural Science Foundation of China (Grant No. 40975093)Shanghai Educational Development Foundation titled "Shuguang Project", P.R. China(Grant No. 03SG30)
文摘The effects of supply temperature and vertical location of inlet air on particle dispersion in a displacement ventilated （DV） room were numerically modeled with validation by experimental data from the literature. The results indicate that the temperature and vertical location of inlet supply air did not greatly affect the air distribution in the upper parts of a DV room, but could significantly influence the airflow pattern in the lower parts of the room, thus affecting the indoor air quality with contaminant sources located at the lower level, such as particles from working activities in an office. The numerical results also show that the inlet location would slightly influence the relative ventilation efficiency for the same air supply volume, but particle concentration in the breathing zone would be slightly lower with a low horizontal wall slot than a rectangular diffuser. Comparison of the results for two different supply temperatures in a DV room shows that, although lower supply temperature means less incoming air volume, since the indoor flow is mainly driven by buoyancy, lower supply temperature air could more efficiently remove passive sources （such as particles released from work activities in an office）. However, in the breathing zone it gives higher concentration as compared to higher supply air temperature. To obtain good indoor air quality, low supply air temperature should be avoided because concentration in the breathing zone has a stronger and more direct impact on human health.
文摘针对余吾煤业N1100工作面实行“高抽巷+Y型通风”治理瓦斯模式,应用流体力学模拟软件Comsol对不同进风量下以及高抽巷不同位置下Y型通风工作面采空区流场、瓦斯浓度场的分布进行了模拟研究,研究表明当进风量增大至2328 m^(3)/min时,工作面瓦斯浓度已经降低至安全作业浓度以下;模拟显示“高抽巷+Y型通风”联合采空区埋管对瓦斯治理效果较为明显,结合现场实际考察提出高抽巷最佳垂直位置为40~55 m.
