室内空气稳定性对交互呼吸过程的影响研究

发布时间：2019-01-27 11:49

【摘要】：室内人体的交互呼吸过程会对室内空气品质和室内污染物的控制产生很大的影响,这将直接影响在室内生活工作者的身体健康。为了了解室内空气稳定性对人体交互呼吸过程的影响规律,本文中重点讨论了不稳定型、中性型和稳定型分别对人体呼吸气流所产生的影响,并分析了造成这些影响的原因。本研究利用室内空气稳定性实验室实验,通过不同的加热模式,营造出三种不同的室内空气温度梯度环境;设置呼气假人和吸气假人,并利用发烟装置发烟,从而达到了呼吸气流可视化研究的目的;通过对呼吸气流的运动轨迹进行拍照对比研究其运动规律。此外,借助计算流体动力学模拟方法,利用模拟软件对实验室建立等比例模型,选择CO2作为污染物运动的示踪气体,对模型进行数值模拟计算,通过分析CO2浓度分布规律得出呼吸气流运动规律。并将实验结果与模拟计算结果对比分析。本文中研究结果表明,在重力加速度为0的条件下,对比不稳定型、中性型和稳定型的模拟结果发现完全一致,说明室内空气稳定性必须以重力存在作为前提。在重力加速度为-9.8 m/s2的条件下,实验与模拟结果一致显示,不稳定型会显著地促进气流在竖直方向上产生脉动,增强呼气主流对周围空气的卷吸作用,污染物的扩散范围更大,由于气流受到浮力作用会促使其向上流动,污染物很难停留在呼吸区域。与此相反,稳定型会显著抑制气流在竖直方向上的湍流扩散,呼气主流难以与周围空气掺混,污染物扩散范围小,使得污染物聚集在半空中,凝滞悬浮在呼吸区域,几乎全部被吸入鼻腔。中性型的结果介于不稳定型与稳定型之间。因此,室内空气稳定性对室内人体交互呼吸过程中污染物的扩散规律有着十分显著地影响,对有效地排除室内空气污染物、提升室内空气品质与设计更为合理的通风系统具有重要意义。
[Abstract]:The interactive breathing process of indoor human body will have great influence on indoor air quality and the control of indoor pollutants, which will directly affect the health of indoor living workers. In order to understand the influence of indoor air stability on human interactive breathing process, the effects of unstable type, neutral type and stable type on human respiratory flow are discussed in this paper, and the causes of these effects are analyzed. In this study, three different indoor air temperature gradient environments were created by using indoor air stability laboratory experiments and different heating modes. The purpose of visualizing breath flow is achieved by setting breath dummy and inspiratory dummy, and smoking device is used to study the movement regularity of breath flow. In addition, with the help of the computational fluid dynamics simulation method and using the simulation software to establish the equal scale model of the laboratory, CO2 is selected as the tracer gas of pollutant movement, and the model is numerically simulated. By analyzing the distribution of CO2 concentration, the law of respiratory airflow movement was obtained. The experimental results are compared with the simulated results. The results show that the simulation results of unstable, neutral and stable types of indoor air must be based on the existence of gravity when the acceleration of gravity is 0. Under the condition of -9.8 m/s2 gravity acceleration, the experimental and simulated results show that the unstable type can significantly promote the pulsation of the air flow in the vertical direction and enhance the entrainment of the expiratory mainstream to the surrounding air. The diffusion range of pollutants is larger and it is difficult to stay in the respiratory region because the air flow is promoted by buoyancy. On the contrary, the stable type can significantly inhibit the turbulent diffusion of the air in the vertical direction, the main stream of breath is difficult to mix with the surrounding air, and the range of pollutant diffusion is small, so that the pollutants are concentrated in the mid-air and suspended in the breathing area. Almost all were inhaled into the nasal cavity. The result of neutral type is between unstable type and stable type. Therefore, the stability of indoor air has a significant effect on the diffusion of pollutants in the process of indoor interactive respiration, and it can effectively eliminate indoor air pollutants. It is important to improve indoor air quality and design more reasonable ventilation system.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU831.1

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