房间通风量的测量与室内局部区域通风效果的评价

发布时间：2018-03-01 12:37

本文关键词： 示踪气体通风量非均匀性局部区域通风有效通风量　出处：《清华大学》2013年硕士论文　论文类型：学位论文

【摘要】：随着国民经济的发展和人民生活质量的提高，舒适和健康的建筑环境逐渐成为人们生产和生活的基本需求。通风是室内环境营造的重要手段之一：通风量不足将导致一系列健康问题，而通风量过大则可能导致较大的能耗；另一方面，不合理的气流组织使得进入室内的空气不能得到有效利用。本文以此为背景，针对房间通风量的测量和室内局部区域通风效果的评价中的四个问题开展了研究。本文的主要工作与成果如下：（1）研究了利用示踪气体测量风道风量的方法，并进行了装置开发。本文首先提出了测量方法和系统，并分析了其适用性。其后对测量中关键的掺混长度给出了定义，通过理论和实验分析了影响因素，并通过实验指出了利用风道中的扰动部件和优化释放管可增强掺混效果。基于此，本文进行了测量装置的开发，通过装置的实测结果说明了测量方法优点，并介绍了其应用。（2）分析了室内均匀性和下降法测量中的问题，介绍了有效风量指标。本文建立了室内多区域模型，，通过分析得出当室内无源时不均匀房间中各区域对数浓度曲线的衰减斜率相同。进一步，本文指出了下降法拟合得到的“换气次数”并非房间真实的换气次数，并针对有固定出风口的房间分析了准确测量的可行性。本文阐述了在房间非均匀时采用有效通风量指标在测量和评价上的优势。（3）建立了等效源模型，提出了局部区域通风效果的综合评价指标和方法。本文通过指标对比分析了局部纯净风量的优势和不足。基于马尔可夫过程基础上建立了等效源模型，并提出了采用局部纯净风量、等效源强度（区域浓度）和排污潜力三种指标综合评价局部区域的通风效果和剩余的排污潜能，给出结合CFD工具简便计算局部纯净风量、等效源强度和排污潜力的简便方法。（4）简要分析了非恒定条件对通风效果的影响，得出了一些初步的结论。本文通过分析说明了均匀混合时以瞬时风量的绝对值积分得到的时均风量与时均有效风量相差较小，指出了工程中以测量得到的有效风量作为时均风量进行设计和评价所带来的误差很小。本文的研究成果加深了对房间通风效果的规律性认识，有助于房间的整体通风的合理测量与评价，以及室内局部区域通风的优化设计。
[Abstract]:With the development of the national economy and the improvement of the quality of life of the people, The comfortable and healthy building environment has gradually become the basic demand of people's production and life. Ventilation is one of the important means of indoor environment construction: insufficient ventilation will lead to a series of health problems, while excessive ventilation may lead to greater energy consumption; On the other hand, the unreasonable airflow organization prevents the air entering the room from being used efficiently. This paper studies four problems in the measurement of room ventilation and the evaluation of ventilation effect in indoor local area. The main work and results of this paper are as follows:. 1) the method of measuring air volume by tracer gas is studied, and the device is developed. In this paper, the measurement method and system are put forward firstly, and their applicability is analyzed. Then, the key mixing length is defined, and the influencing factors are analyzed through theory and experiment. It is pointed out through experiments that the mixing effect can be enhanced by using the disturbance components in the air duct and the optimized release tube. Based on this, the measuring device is developed, the advantages of the measuring method are explained by the measured results of the device, and its application is introduced. The problems in indoor homogeneity and descent measurement are analyzed, and the effective air volume index is introduced. In this paper, the indoor multi-region model is established, and the attenuation slope of logarithmic concentration curve of each area in a non-uniform room is found to be the same when the room is passive. This paper points out that the "air exchange times" obtained by the descent fitting method are not the true air exchange times of the room. The feasibility of accurate measurement is analyzed for the room with fixed air outlet. This paper describes the advantages of effective ventilation index in measurement and evaluation when the room is non-uniform. The equivalent source model is established, and the comprehensive evaluation index and method of local area ventilation effect are put forward. In this paper, the advantages and disadvantages of local pure air volume are compared and analyzed. Based on the Markov process, the equivalent source model is established, and the local pure air volume is proposed. The ventilation effect and residual discharge potential of local area are evaluated synthetically by three indexes of equivalent source strength (regional concentration) and discharge potential. A simple and convenient method for calculating local pure air volume, equivalent source strength and discharge potential is presented by using CFD tool. The influence of unsteady condition on ventilation effect is analyzed briefly, and some preliminary conclusions are obtained. In this paper, it is shown that the time average air volume obtained by the absolute integral of the instantaneous air volume is smaller than that of the time average effective air volume when the mixture is uniformly mixed. It is pointed out that the error caused by the design and evaluation of the effective air volume measured in engineering is very small. The research results of this paper deepen the understanding of the regularity of the ventilation effect of the room, and contribute to the rational measurement and evaluation of the overall ventilation of the room, as well as the optimum design of the ventilation in the local area of the room.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU834

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