大空间建筑分层空调两种典型送风系统区域间换热特性研究

Inter-zonal heat transfer characteristics under two typical air supply systems of stratified air conditioning in large space buildings

结合实验和CFD模拟方法,研究了采用柱状下送风系统和侧壁喷口送风系统时区域间对流转移热量和区域间温差换热系数的计算方法,讨论了2种系统区域间换热情况。在缩尺实验室中,研究了无内热源且具有相同排风比的实验案例。根据实验结果,对CFD模拟得到的竖直温度分布和冷负荷结果进行了验证。通过将整个空间竖直划分为4个区域,计算得到区域间温差换热系数。结果显示:采用柱状下送风系统,温度梯度引起的热传导占主导作用;采用侧壁喷口送风系统,温度梯度引起的热传导和气流流动引起的气流换热量都不容忽视;区域间温差换热系数受送风方式和区域划分的影响,并与局部湍流强度有关。

Combined with experiment and CFD simulation methods,this paper studies the calculation methods of interregional convective heat transfer and inter-zonal temperature difference heat transfer coefficient using floor-level side wall air supply system and sidewall nozzle air supply system,and discusses the inter-zonal heat transfer.In the scaled laboratory,the experimental cases with the same exhaust air ratio without an internal heat source are studied.According to the experimental results,the vertical temperature distribution and cooling load results obtained by CFD simulation are verified.By dividing the whole space vertically into four zones,the inter-zonal temperature difference heat transfer coefficient is obtained.The results show that the heat conduction caused by temperature gradient plays a dominant role in floor-level side wall air supply system,but for sidewall nozzle air supply system,the heat conduction caused by temperature gradient and the heat transfer caused by mass flow can not be ignored.The inter-zonal temperature difference heat transfer coefficient is influenced by supply air mode and regional division,and is related to local turbulent viscosity.