Air Diffusion Performance of Variable Work Area Attachment Ventilation in Big Underground Space

In view of high energy consumption of environmental control system in large underground space and the fact of changing AC working area in actual operation, based on the attachment ventilation, a variable working area attachment ventilation for large underground space is proposed. With the help of numerical simulation, an orthogonal experiment was firstly carried out to study the influence of the gap width between the deflector and the wall, the character thickness of the jet flow, and the influence of the rectangular column span on the flow ratio under the isothermal conditions. At the same time, through the dimensional analysis, the relationship between the flow ratio q and the ratio between the gap width and the jet characteristic thickness x/δ0.5 is obtained, that is, the flow distribution law of the deflector. Secondly, the air diffusion performance of variable working area attachment ventilation is compared with mixing ventilation and square column attachment ventilation, and the results suggest that compared to the other two air supply methods, variable working area attachment ventilation can effectively reduce the air age of the breathing area and has better energy saving effect.