关于地下车库通风与排烟设计问题的讨论

本文分析了地下汽车库全面通风换气量取值的计算方法,通过对有害气体密度以及上升气流的分析,给出地下车库不需从下部排风的根据和理由,得出了地下汽车库的通风和排烟系统可以合二为一这个结论,而且《采暖通风与空气调节设计规范》(GB50019—2003)的规定“当放散气体的密度比空气重,建筑内放散的显热不足以形成稳定的上升气流而沉积在下部区域时,宜从下部区域排出总风量的三分之二,上部区域排出总排风量的三分之一”并不适合地下汽车库。最后根据实例的计算进一步证明该结论。

Discussion on Ventilation and Smoke Exclusion of Under Ground Garages Design

The calculation of air exchange volume of general ventilation in under ground garages were presented in this paper.The harmful gas density and updraft were analyzed in order to advance some reasons why exhaust air needs not be done from underside of under ground garages, so that both ventilation system and smoke exclusion one could be united. In conclusion, the standard "When the density of the emission gas is greater than air, it will deposit in the lower space due to the sensible heat emitted from the building is not enough to form the steady updraft. Thus it is necessary to exhaust 2/3 of the total air flow rate from the lower space and to exhaust the rest from the upper space."of the Code for Design of Heating, Ventilation and Air Conditioning, is unfit for the ventilation in under ground garages.