室内初始温度较高条件下的瞬态自然通风  

Transient natural ventilation in a room with high initial temperature

作　　者：杨秀峰[1,2] 钟珂[1] 亢燕铭[1] 左滨[2] 

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]扬州大学能源与动力工程学院,江苏扬州225127

出　　处：《扬州大学学报（自然科学版）》2012年第4期68-73,共6页Journal of Yangzhou University：Natural Science Edition

基　　金：国家自然科学基金资助项目(40975093);江苏省高校自然科学基金资助项目(09KJB560004)

摘　　要：在已有理论模型的基础上,给出一个描述室内初始温度较高条件下瞬态自然通风的改进模型.该模型与已有模型的主要区别在于其认为室内新形成的热空气层不是充分混合的,而是由紧靠天花板的热空气薄层及其下方的热空气层两部分组成.经验证,改进模型的预测精度好于已有模型.利用改进模型分析室内初始温度较高条件下的瞬态通风过程后发现,无量纲有效通风面积或室内空气初始浮升力越小,室内原有热空气层的上界面下移低于稳态热分层界面的现象越明显,无量纲的瞬时通风量越小.此外,无量纲有效通风面积越小,稳态时的热分层界面高度和无量纲通风量均越小,而室内空气初始浮升力变化不会影响热分层界面高度和无量纲通风量的稳态值.A modified theoretical model is proposed based on an existing model to examine the transient natural ventilation when the room is initially warmer than the exterior. The main difference between the modified model and previous model is that the newly-formed buoyant layer is regarded as composed of a near-ceiling layer and a warm layer below it rather than being well-mixed. The modified model is proved to perform better than the existing model and is then employed to examine the transient natural ventilation. The results indicate that the smaller the dimensionless effective vent area or the original buoyancy of indoor air is, the more significant of the extent to which the upper interface of the original warm layer overshoots its steady-state depth and the lower the dimen- sionless flow rate. The smaller the dimensionless effective vent area is, the lower steady-state interface height and the steady-state dimensionless flow rate are. In contrast, the change of the original buoyancy of indoor air can not affect the steady-state values of the interface height and the dimensionless flow rate.

关 键 词：瞬态自然通风 改进模型 有效通风面积 初始浮升力 

分 类 号：TU834.1[建筑科学—供热、供燃气、通风及空调工程]