【作者】 刘敏；

【导师】 亢燕铭；

【作者基本信息】 东华大学 ， 环境科学， 2008， 硕士

【摘要】 室内环境对人体健康有着重要的影响,空调系统的主要目的就是为室内人员创造一个健康、舒适的环境。但是随着对颗粒物污染研究的深入,有关颗粒物对人体的危害已成为主要问题。室内的主要污染物以气体和颗粒物的形式存在,合理的通风系统对室内污染物的清除具有十分重要的作用。但是大多数通风和空调系统的设计没有考虑气流中的颗粒物沉积,而许多流行病学的研究都表明空气污染性健康问题与可吸入颗粒物(PM₁₀)有关。对于办公室以及其他类似的工作环境、医院和学校等,主要的颗粒污染源是室外空气。因此,本文对不同空调房间室内颗粒物的演变规律进行了研究。本文根据颗粒物的动力学特性,采用FLUENT程序,利用所得的背景颗粒物测量资料,选取混合通风房间和地板送风两种代表性的送风方式,对室内气流、温度和颗粒物浓度分布进行了数值模拟。结果发现室内粒子浓度对室外粒子浓度具有直接的依赖性;并且地板送风送入的空气更洁净,特别是工作区与人员呼吸区,与混合通风相比更加符合人体舒适性的要求。通过对粒子源位于不同空调房间不同高度位置处室内颗粒物的运动、扩散和沉积的模拟结果分析,一方面发现颗粒物对人体健康的影响与颗粒物污染源的位置有关,当室内污染源位于办公平面时对人体健康危害最大;另一方面,混合通风比地板送风系统在人体上形成的沉积量大,而地板送风相对混合通风在地板上的沉积量大很多,但是如果能保证定期仔细清洁地板送风房间的地面粒子沉积,地板送风系统对室内不同位置粒子污染的抑止和清除作用都优于混合通风。同时,还分析了典型状况下室内细粒子浓度的时间演化效应。更多还原

【Abstract】 The most important environment in relation to our health is the indoor environment. The main purpose of HVAC systems is to provide a healthy and comfortable environment for the occupants of the space. But more and more concern is focusing on the indoor particle pollution and its effect on human health in the current days.The typical contaminants in buildings are presence in the form of gases and particles. Ventilation plays a key role in the dilution and removal of contaminants within indoors. But most ventilation and air conditioning systems are designed without much concern about how separating particles behave in ventilation air flow, and many epidemiological studies showed that air pollution related health problems have extensive relation to inhalable particles. For office and other similar work-related environments, hospitals, schools etc, the main source of pollutants is often outdoor air. In the present paper, the characteristics and evolution of particle size distributions in different ventilation rooms.Based on the aerosol particle dynamic equation and the monitoring date of Chengdu’s outdoor particle concentration, the FLUENT code is employed to simulate the particle motion and deposition in Mixing Ventilation (MV) and Under-Floor Air Distribution (UFAD) rooms, and the characteristics of rooms airflow, temperature and particle concentration are evaluated and estimated. The numerical results show that the variation of indoor particle concentration is directly influenced by outdoor particle concentration; and compared to MV rooms, the supply air within UFAD rooms is much cleaner, especially at the work area and respiratory district, and more in line with the requirements of human comfort.In addition, the results of the simulations about particle movement, diffusion and deposition in different ventilation rooms and different height indicate that: first, particle pollution on human health effects is relevant to pollution sources location, particularly pollution sources located in official surface. Second, the amounts of particle deposition on persons in MV rooms are more than UFAD rooms, whereas particle depositions on floors are reverse, but if being able to ensure to clean depositions in UFAD rooms regularly, UFAD is better than MV at restraining and eliminating particle contaminants which at different locations. Meanwhile, the time evolution of fine particle in MV and UFAD rooms under typical conditions is analyzed.更多还原