Study on ventilation standard based in ventilation efficiency

由于房间内的通风效率并不总是均匀分布的，因此需要一个衡量关注点或关注局部区域内通风效率的指标。局部通风效率通常由局部区域的平均浓度与从房间排出的空气的平均浓度的比率来表示。根据空气的年龄理论，房间内的平均浓度与污染物的平均停留时间相对应。区域平均浓度的计算是指污染物在区域内的平均停留时间的计算。它可以是整个房间的一部分，可以被视为一个占用区。在此，在这项研究中，新的通风效率指标（VF，Tp和L-PFR）的开发和分析。引入访问频率VF和污染物在局部区域的平均停留时间Tp，分析了污染物在局部区域的平均停留时间。值O 关于我们 f VF受房间中局部区域位置的强烈影响，换句话说，局部区域在房间的整个流场上的位置。Tp表示局部域中的流型的性质。由于VF和Tp表示区域平均浓度的机制，因此它们与局部吹扫流量（L-PFR）密切相关，局部吹扫流量（L-PFR）表示用于定义区域平均浓度的空气流量。对VF、Tp和L-PFR进行了数值分析，并进行了模型试验验证。模型由（x）：（y）：（z）= 1.5m：0.7m：1.0m的空腔组成，空腔配有0.02m宽的入口和出口槽。这个空腔被分成三个较小的空腔，由玻璃隔开。中心工作腔（0.3m宽，对应于模型室）是进行测量的位置，另外两个腔（0.2m宽）是再现与工作腔相同流型的位置（保护腔）。四个边界（天花板，地板，灯光和左墙）由水冷铝热交换器组成，以控制墙面温度。在此基础上，对实际办公空间和实验模型的VF、Tp和L-PFR进行了数值模拟分析。少

Since ventilation efficiency in a room is not always uniformly distributed, an index for measuring ventilation efficiency at a concerned point or in a concerned local domain is required. Local ventilation efficiency is often represented by the rate of the averaged concentration of the local domain to that of exhausted air from the room. From the age theory of air, it is well-known that the averaged concentration in a room corresponds to the mean staying time of contaminant. Evaluating the domain averaged concentration means evaluating the average staying time of contaminant in the domain. It can be only one part of the whole room and can be considered as an occupied zone. Here, in this research, new index of ventilation efficiency (VF, Tp and L-PFR) are developed and analyzed. Visitation frequency (VF) and the average staying time of contaminant for one visitation in the local domain (Tp) are introduced to analyze the average staying time of contaminant in the local domain. The value o … More f VF is strongly affected by the position of the local domain in the room, in other words, the position of the local domain on the whole flow field of the room. Tp represents the property of the flow pattern in the local domain. Since VF and Tp indicate the mechanism of the domain averaged concentration, they are deeply related to local purging flow rate (L-PFR) which represents the air flow rate for defining the domain averaged concentration. Analysis of VF, Tp and L-PFR are based on the numerical method.In order to validate the results of numerical simulation, model experiment was carried out. A model was composed of (x) : (y) : (z) = 1.5m : O.7m : 1.Om cavity equipped with a O.02m width inlet and outlet slots. This cavity is divided into three smaller cavities, which is seperated by glass. The center working cavity (O.3m width, correspondance to model room), is the location where the measurements were performed, and the two other cavities (O.2m width) is the location where the same flow pattern as in the working cavity was reproduced (Guard cavity). Four boundaries (ceiling, floor, light and left walls) consists of water-cooling aluminium heat exchanger to control the wall surface temperature. Detailed data for flow fields are accumulated from this model experiment.Then, numerical simulations are carried out to analyze VF, Tp and L-PFR, concerning a actual office space and experimental model. Less