上海地区分户式供暖排放NO2对室内外环境空气质量影响数值模拟研究
Numerical simulation study on influence of NO2 emitted from household heating on indoor and outdoor air quality in Shanghai
摘要：
以上海市区6层居住建筑为例,采用CFD数值模拟方法研究了室外风速、室外风向、燃气壁挂炉排放等级等因素影响下分户式供暖排放的NO2的扩散特性,并将模拟结果与现有标准中NO2浓度限值作了比较。结果表明:自然通风会使壁挂炉排放的NO2由室外向室内传输,导致室内NO2浓度超标,壁挂炉排放等级越低,室内外传输导致的超标问题越严重;风向越接近正北,室内和区域微环境内NO2浓度总体水平越高;建筑顶层污染物浓度最高,底层最低;区域微环境中NO2浓度分布受壁挂炉排放等级、室外风速和风向等因素影响显著,排放等级越高、风速越大,越有利于污染物在环境中的扩散稀释。
Abstract：
Taking a six-storey residential building in Shanghai as an example, the diffusion characteristics of NO2emitted from household heating under the influence of outdoor wind speed, outdoor wind direction and emission level of wall-mounted gas boilers are studied by CFD numerical simulation method. The simulated results are compared with the concentration limit of NO2in the existing standard. The results show that natural ventilation can promote the transmission of NO2emitted by wall-mounted boilers from outdoor to indoor, which results in indoor NO2concentration exceeding the standard limit. The lower the emission level of wall-mounted boilers is, the more serious the problem of exceeding the standard limit caused by indoor and outdoor transmission is. The closer the wind direction is to the north, the higher the overall level of NO2concentration in the indoor and regional microenvironment is. The NO2concentration is highest on the top floor and lowest on the ground floor. The NO2concentration distribution in the regional microenvironment is significantly affected by the emission level of the wall-mounted boilers, the outdoor wind speed and the wind direction. The higher emission level and the higher wind speed are more conducive to the diffusion and dilution of pollutants in the environment.
Keywords:household heating; wall-mounted gas boiler; NO2; diffusion characteristic; air quality; emission level; wind speed; wind direction