【作者】 王勇；

【导师】 钟珂；

【作者基本信息】 东华大学 ， 供热、供燃气、通风及空调工程， 2013， 硕士

【摘要】 对于大多数民用建筑而言,风压作用下的自然通风是通风的主要形式,而自然通风也是改善室内空气品质和热湿环境的重要手段之一。显然,稳定的通风换气对于维持室内健康良好的环境是十分重要的。一般情况下,在应用自然通风公式时,常将建筑近似简化为封闭的长方体。但是,实际情况下,建筑的住户会打开窗户通风改善室内空气环境(特别是春季和秋季),如果建筑立面上的窗户开启较多,会对街谷的流场和压力场形成一定的影响,进而影响自然通风公式的应用。此外,当建筑的一个立面接受阳光辐射,表面被加热,在受热面附近会形成向上的热羽流,进而改变街谷内的气流分布。因此,热效应也是影响街谷气流分布的重要因素之一。在对夏热冬冷地区典型城市上海的居住建筑窗户开启率情况调查和建筑壁面和地面与背景空气的温差进行测量后,以调查和测量的数据结果为依据,针对不同的窗户开启率(WOP)和太阳辐射条件情况,利用数值模拟方法对街谷流场和温度场进行研究。本文研究结果表明：窗户开启率对迎风建筑两侧的静压差影响较小,可以忽略不计,但开启率对背风建筑静压差的影响显著,在计算自然通风量时,必须考虑窗户开启率对背风建筑通风量的影响；考虑到建筑不开窗情况是获取房间通风口两侧静压差的基本模型,故本文建议设置流量系数的修正系数k将其他房间开窗通风对计算房间通风口两侧静压差的影响考虑进去,并给出了修正系数k取值范围：窗户开启率为4.44%时,μ的修正系数k=0.43～0.49；开启率为9.78%时k=0.32～0.36；通过定义静压差影响因子w,分析发现太阳辐射对于背风建筑附近静压分布的影响大于迎风建筑,且对于迎风建筑,背风面散热情况影响最大,迎风面散热情况的影响最小；街道内热效应对建筑房间静压分布和自然通风的影响效果存在临界风速(Vc),不同散热强度时对应的临界风速(Vc)不同。更多还原

【Abstract】 For most civil buildings, wind-driven natural ventilation is the main approach of natural ventilation, and also an important way of improving indoor air quality and thermal environment. It is obvious that stable air flow rate is necessary to maintain a healthy and comfortable indoor air quality and thermal environment in the natural ventilation room.When using the equation of natural ventilation, the building is usually regarded as a block. However, in fact people will open windows for better indoor environment (especially in spring and autumn), and if the most windows of the side wall of a building are open, then the air flow of the street canyon may be influenced, thus affect the applying of the natural ventilation equation. In addition, when a side wall of a building receive solar radiation and is heated, the upward buoyancy near the side wall will affect the air flow in the street canyon, thus thermal effect is also an important factor.The present study investigated the window opening percentage (WOP) and the temperature difference between back ground air and the heated side wall in Shanghai, based on the data, the study discuss the flow field and temperature field by numerical simulation with different WOPs and thermal conditions.The results show that the effect of WOP on the static pressure difference (SPD) of the upwind building is negligible, while that of the downwind building can not be ignored. Therefore it is necessary to consider the WOP effect when calculating the air flow rate of the natural ventilation rooms in the downwind building. In order to obtain an applicable correction for air flow rate calculation of wind-driven natural ventilation, a correction factor, i.e. k, is introduced and the ranges of κ for different WOPs are also determined from the analysis, and0.43<k<0.49when the WOP is4.44%; while0.32<k<0.36when the WOP is9.78%. Since the thermal conditions may affect the static pressure distribution around buildings, an influence factor w is defined to discuss this effect. The values of w decrease with the increase of wind speed for both upwind and downwind buildings, and it appears that the influence of thermal conditions on the pressure distributions of downwind buildings is greater than that of upwind buildings. When VH reaches a critical value, i.e. Vc, the values of w are below5%, and the influence of thermal effects on the pressure distributions can be ignored. The values of Vc depends on the thermal conditions.更多还原