Control and use of stack effect from the view of natural ventilation and fire safety

近年来，出于节能和改善室内空气品质的需要，采用自然通风的建筑越来越多，其中利用中庭或竖井促进烟囱通风的规划并不少见。在传统的研究中，“无菌管”方案被频繁使用，但由于中庭设计和建筑/中庭使用的诸多限制，一直不被设计师所青睐。至于其他解决方案，例如使用大量百叶窗将相邻空间与中庭分隔开，除了初始成本高之外，很难确保所有百叶窗都正常工作，因为它们仅在紧急情况下使用，并且如果其中一个百叶窗未能关闭，则疏散行为可能会延迟或失败。因此，研究合适的烟气控制方法是当务之急.本论文探讨自然通风与防排烟共用一个系统的可能性，并提出一种新的防排烟方法，以确保采用自然通风规划的建筑物的消防安全。作为原型建筑，太阳能烟囱的空间可以通过吸收太阳辐射促进自然通风，同时使中性面停留在烟囱内，通过压差实现防烟。通过缩尺模型实验和CFD计算证实了这一概念。

For the purpose of energy conservation and requirements for improving indoor air quality, buildings employing natural ventilation are increasing recently, among which the planning of utilizing atria or vertical shafts to promote stack ventilation is not scarce. In conventional researches, 'Sterile tube' solution has frequently been used, but due to the many restrictions on the atrium design and the use of the building/atrium, it is always not favored by designers. As for the other solutions, such as using a great number of shutters to separate adjacent spaces from the atrium, besides high initial cost, it is difficult to ensure that all shutters work properly, because they are only used in case of emergency and if only one of those shutters fails to close, evacuation behavior may be delayed or fail. Proper smoke control method is urgent to be found out. In this thesis, the possibility of using the same system both for natural ventilation and smoke control is examined.To secure fire safety of a building with natural ventilation planning, a new smoke control method is proposed in this research. As the prototype building, the space of the solar chimney can be used to promote natural ventilation by absorbing solar radiation, and at the same time making the neutral plane stay in the chimney, smoke prevention can be realized by pressure difference. This concept is confirmed by reduced scale model experiments and CFD calculation.