Research on a Secondary Airflow-Relay System to Improve Ventilation Performance of Nozzle Supply in Large Space Buildings

Abstract

In large space buildings, jet flow nozzle is usually used for ventilation and air conditioning. A secondary airflow-relay system is proposed for situations that building span is larger than the primary jet flow range. A physical experiment is conducted to investigate the effect of such secondary airflow-relay; a CFD model is built up to research the secondary airflow velocity and relative location of primary and secondary terminal on the ventilation performance. The CFD result is validated by experimentally measured vertical temperature distribution in certain points. Various indices including ADPI, PD and CV of temperature and velocity at breathing level is used to quantitatively evaluate the ventilation performance of different configurations. It is found that the secondary airflow system should be properly specified in order to improve the ventilation performance of a large space building. The secondary airflow-relay may potentially increase the cooling energy consumption as indicated by CFD result.