湿热季地下车库诱导射流改善表面结露和CO污染

Application of Inductive Air Jet to Underground Garage for Reducing Both the Surface Condensation and CO Pollution under Hot and Humid Season

摘要:

在湿热季节地下空间“机械排风+自然进风”条件下，表面对流换热强度小，加上土壤大热惯性体作用，使表面结露极难抑制。同时，该通风设置对车库类地下空间尾气污染控制不利。本文针对上海某高层办公楼纵深型地下车库空间湿热季内表面严重结露问题，在原通风系统分布式均匀排风主导的情况下，测试分析了表面结露状况；改进设计了一套诱导射流系统，兼顾墙面贴附射流和地面冲击射流效应，提高近壁气流速度和湍流换热水平，使得表面对流换热和表面温度明显升高，在湿热季车库通风时段显著改善表面结露问题。同时，诱导射流解决了原有系统在纵深区域CO气态污染排除不畅、呼吸区积聚浓度偏高的问题。

Abstract:

Under hot and humid climate, it is difficult to inhabit the surface condensation in underground space with the combined system of mechanical exhaust and natural air supply. This situation results from the low surface convection and large thermal inertia of the soil. Meanwhile, such ventilation system is not conducive to reduce the exhaust pollution in such underground space as garage. This study tries to resolve the serious condensation problems of a large underground garage with the deeply spatial pattern in Shanghai, which is ventilated by the dominant effect of uniformly distributed exhausts. Test and analysis of surface condensation are carried out under the originally equipped system. An inductive air-jet system, taking into account the attached effect along wall and impinging effect on the floor, is presented. It is applied to intensify the air velocity and turbulent level near the surface, and thus to increase the surface heat transfer and temperature. It is confirmed that the surface condensation is significantly reduced under hot and humid season through the inductive air jets. Meanwhile, the improved system also reduces the accumulation of concentration of CO gaseous pollution at the breathing zone in the garage.