Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 103 === The inclined air-curtain (IAC) fume hood was successfully developed in previous research. By appropriately adjusting the physical parameters (e.g., suction velocity and blow velocity) and geometries, the IAC hood has been proved as an “almost zero-leakage” apparatus. However, previous research did not show the performance and optimized operation parameters when a high-heat load pollutant source was generated in the hood. The aim of the present work is focused on studying the effects of the high-heat plume on the flow field and the leakage of tracer gas from the sash opening. Laser-assisted smoke flow visualization technique was firstly employed to obtain the flow characteristics. The flow visualization results provided a clear picture for optimizing the operation parameters and strategy for high-heat-load operation. The standard tracer-gas concentration test methods (EN14175-7:2012 and ANSI/ASHRAE 110-1995) were used to examine the leakage levels of the IAC hood under the static, dynamic, and occupied conditions. The results showed that a negligibly small leakage level was obtained for the static, dynamic, and occupied conditions when the IAC hood was operated at the face velocity 0.32 m/s and sash height 50 cm. To obtain a high containment efficiency, the required face velocity (or suction flow rate) of the IAC hood is drastically smaller than that of a high performance conventional fume hood. The difference is about 60%.
|