A Study on the Improvement of Ventilation Rate Using Air-flow Inducing Local Exhaust Ventilation System

摘要

In the case of the canopy hood, which is one of the existing Local Exhaust Ventilation systems, there appears to be a weakness in that when the level of ventilation is insufficient or when the effluent′s buoyancy effect is significant, a partial amount of effluent seeps out and accumulates on the upper workspace. This study proposes the Air-flow Inducing Local Exhaust Ventilation system (AI-LEV), which can increase the ventilation rate without increasing the use of artificial energy by extracting the high-heat or high-density effluent that accumulates on the upper workspace. CFD (Computational Fluid Dynamics) was used to examine the effectiveness of the AI-LEV. The thermal characteristics of the mock-up chamber, along with the introduction of the canopy hood, was examined and the physical reproducibility of the CFD was verified experimentally. Compared to the existing Local Exhaust Ventilation systems, the introduction of AI-LEV led to a radical decrease in temperature through the overall interior. In addition, the high-temperature air that accumulated in the chamber′s upper space was extracted smoothly outside the chamber through the inducement of the AI-LEV. The AI-LEV showed a 0.5-1.8 oC decrease in temperature in a space larger than 1.5m from the floor compared to the existing Local Exhaust Ventilation systems.