A Numerical Study of the Indoor Thermal Environment in an Air-conditioned Large Space Building

The characteristics of a stratified air-conditioning system, only maintaining task zone's certain air temperature and air velocity of large space building, are studied in an airport terminal building. The indoor thermal environment is discussed by means of Computational Fluid Dynamics (CFD) software under various conditions of supply air temperature, velocity, height and angle of incidence. The mean velocity, mean temperature, non-uniform coefficient of velocity distribution, non-uniform coefficient of temperature distribution, air diffusion performance index are adopted as the thermal comfort indices to evaluate the air velocity and temperature fields in the occupied region. Based on the analysis of heat load in the top zone, the opening where it locates and its sizes is confirmed. The primary design schemes are modified and further simulations are undertaken for modified flow fields in terms of above evaluation indices. The upper opening is disadvantageous for saving energy in summer. CFD technology that predicts airflow distribution is an efficient tool to evaluate the implementation of different supply air parameters in the building and to assist in decision making concerning building structure and passenger's thermal comfort problems.