大空间建筑下送风分层空调系统区域间换热特性研究

Study on Inter-zonal Heat Transfer for Large Space Buildings with Floor-level Side Wall Air-supply System

本文采用实验和计算流体力学(CFD)方法,研究了带有柱状下送风系统的大空间建筑中,由气流换热和温差导热组成的对流转移热的计算方法。在缩尺模型实验室中,研究了三种不同排风比的热环境和负荷特性,根据实验得到的中心线垂直温度分布和空调冷负荷验证了CFD模拟结果,并基于相似理论,将缩尺数值模型拓展至全尺寸工况模拟。结果表明:在柱状下送风系统中,温差引起的热传导在区域间换热中起主导作用。将整个室内空间垂直方向划分两个区域,原型建筑的区域间传热系数C_(b)在排风比为0、10%、20%时分别为7.92、6.14、3.81 W/(m^(2)·℃)。C_(b)主要受气流状态、区域划分方式和气流组织形式影响,而受屋顶排风方式的影响较小。

This study uses experimental and computational fluid dynamics(CFD)methods to investigate convective heat transfer,heat convection caused by airflow,and heat conduction caused by temperature differences in large-space buildings with floor-level side wall air-supply systems.Three thermal environment experiments with different roof exhaust ratios were conducted in a reduced-scale laboratory to investigate the indoor thermal environment and load characteristics.The CFD simulation results were verified based on the experimentally obtained vertical temperature distribution of the central line and air-conditioning cooling load.Based on similarity theory,reduced-scale numerical models are extended to full-scale configurations.The results show that the heat conduction due to the temperature difference dominates the inter-zonal heat transfer in the floor-level side wall air-supply system.By dividing the entire indoor space into two zones in the vertical direction,the values of inter-zonal heat transfer coefficient C_(b) for the prototype building are 7.92,6.14,and 3.81 W/(m^(2)·℃)at 0,10%,and 20%roof exhaust air ratios respectively.C_(b) is mainly influenced by the airflow characteristics,zonal division,and airflow pattern,whereas it is less affected by the roof exhaust method.