針對傳統的商用箱型廚房排油煙櫃，利用實驗方法探討排油煙櫃的流場特徵與洩漏特性。本研究的傳統的商用箱型廚房排油煙櫃包含三種設計的型式(平板式、槽板式及無平板式)。使用流場可視化的方法，擷取傳統商用排油煙機之水平面及垂直面上的特徵流場照片。使用六氟化硫作為追蹤氣體，藉由偵測六氟化硫的濃度分佈，探討排油煙櫃的洩漏特性。由流場可視化的結果發現，一個迴流泡在排油煙機的左上方形成因為邊界層分離。此迴流泡結構造成排油煙機運轉在大的面速度時，內部的油煙捲出排油煙機的外部。排油煙機內強烈的紊亂氣流，使得內部流體排油煙櫃的兩測及上緣流出，造成濃度洩漏呈現倒U型的分佈。當放置人體模型在排油煙機前方時，將引致強烈的紊亂流動，因此使得排油煙櫃內部的六氟化硫氣體大量地洩漏至排油煙櫃以外的環境中。在高吸氣面速度條件下，物體經過排油煙櫃前方時沒有造成強烈的濃度洩漏。整體而言，傳統的商用箱型廚房排油煙櫃的抽氣性能不佳，需要根據氣動力學的概念作適當的修改。

The flow and leakage characteristics of a conventional commercial box-type kitchen hood were experimentally studied. The conventional commercial box-type kitchen hood included three design configurations (with plate, with slotted plate, and without plate). The characteristic flow patterns in the horizontal and vertical planes of the conventional commercial box-type kitchen hood were captured by flow visualization method. The leakage characteristics of conventional commercial box-type kitchen hood were recorded by SF6 tracer-gas concentration detection technique. A recirculation bubble was formed at the upper left side of the hood due to the boundary layer separation. This recirculation bubble caused the smoke disperse out of the hood when the face velocity of the hood was high. The high leakage concentration was detected around the area of inverted U in the hood face. Placing a mannequin in front of the hood face would induce large turbulent flows, and cause a significant leakage concentration into the environment through the left edge of the hood. The moving object passed through the hood face doesn’t have significant effect for the leakage concentration at high face velocities. Overall, the conventional commercial box-type kitchen hood showed low performance that improvement in aerodynamic design is required.

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