周期性动态送风对室内污染物分布和通风效率的影响

Influence of Periodic Dynamic Air Supply on Indoor Contaminant Distribution and Ventilation Efficiency

室内通风气流组织的设计不当会造成污染物滞留和室内空气品质的下降,特别是在定风速送风工况下,室内形成的稳定流场若存在较大的旋涡或停滞区,会导致污染气体的长时间堆积。为了解决这一问题,在典型通风房间中采用了周期性波动的送风速度,对比了定风速送风和不同周期和振幅的正弦送风工况下室内污染物的分布和通风效率,发现动态波动的送风速度有利于污染物滞留区的消除,为解决这一问题提供了新的方案。动态送风的周期长度允许送风气流在室内充分发展的情况下,相同的振幅周期越小通风效率越高;在相同的周期下,振幅只有超过某一临界值时才会大幅度提高通风效率,并且当振幅大于临界值后,振幅越小通风效率越高。

Improper design of indoor ventilation and air distribution will result in contaminant retention and decline of indoor air quality.Under the condition of constant wind speed,if there is a large vortex or stagnation area in the stable flow field formed indoors,it will lead to the accumulation of polluted gas for a long time.In order to solve this problem,periodic fluctuation of air supply velocity is adopted in a typical ventilation room.And the indoor contaminant distribution and ventilation efficiency under constant wind speed and sinusoidal air supply with different periods and amplitudes were compared.It is found that the dynamic fluctuation of air supply velocity is beneficial to the elimination of contaminant retention area,which provides a new solution to this problem.Under the condition that the period length of the dynamic air supply allows the full development of the air supply in the room,the smaller the period is,the higher the ventilation efficiency is.Under the same period,the ventilation efficiency will be greatly improved only when the amplitude exceeds a critical value,and when the amplitude is greater than the critical value,the smaller the amplitude is,the higher the ventilation efficiency will be.