High-efficiency diffuser based on a normalized evaluation index of jet length and resistance

Abstract

The fan energy consumption caused by the resistance of representative local components, including diffusers, accounts for 10% of building energy consumption. This proportion increases with more stringent requirements for building functionality, intelligence and comfort. This study introduces a high-efficiency diffuser based on a normalized evaluation index of jet length and resistance. The resistance reduction mechanism is analyzed based on the principle of entropy increase. A comprehensive performance evaluation index, the air diffuser effective index (ADEI), is put forward to describe the resistance and jet length of the diffuser.The preliminary results show that compared with the round diffuser, the novel diffuser can mitigate the fluid deformation, weaken the strength of the airflow vortex and reduce the conversion of mechanical energy to internal energy. The jet length and flow resistance of the novel diffuser are respectively 7% longer and 47% lower than those of the round diffuser. The proposed ADEI of the novel diffuser is 56% smaller than the round diffuser.