西安市冬季两典型新建住宅通风量及室内空气质量实测与分析——自然通风及机械通风工况

Measurement and Analysis of Ventilation Rate and Indoor Air Quality of Two Typical Newly-built Residential Buildings in Xi’An in Winter——Natural and Mechanical Ventilation Scenarios

针对西安市设有户式新风系统的两典型新建住宅,测试了冬季门窗关闭自然渗透、开窗通风及机械通风3种通风方式下的通风量及室内污染物浓度。对不同通风方式下的室内空气质量进行了评价与对比,并采用数值模拟对机械通风存在的问题进行了诊断分析。研究结果表明自然渗透下的换气次数为0.17 h^(-1),不同开窗尺度的开窗通风下的换气次数为1.43~3.74 h^(-1),不同运行工况下的机械通风下的换气次数为2.31~4.50 h^(-1)。自然渗透工况室内CO_(2)浓度严重超标,采用开窗通风控制CO_(2)时需保证足够的开窗时间。采用带过滤装置的机械通风系统在雾霾天气可将室内PM_(2.5)浓度控制到远低于限值。6种机械通风测试工况均不能将室内CO_(2)浓度控制在限值以内,气流组织设计不当是主要原因。模拟优化结果表明侧送风口设置在下部排风门缝对角方位为最优的气流组织设计方案。

For two typical newly-built residential buildings with household fresh air systems in Xi'an,the ventilation rate and the indoor pollutant concentrations under three ventilation modes of natural infiltration,windowopening ventilation,and mechanical ventilation in winter were measured.The indoor air quality under different ventilation modes was evaluated and compared,and the problems of mechanical ventilation were diagnosed and analyzed by numerical simulation.The results show that the ventilation rate under natural infiltration is 0.17 h^(-1),the ventilation rate under different window-opening sizes is 1.43~3.74 h^(-1),and that under mechanical ventilation with different operating conditions is 2.31~4.50 h^(-1).The indoor CO_(2) concentration under the natural infiltration mode is seriously beyond the standard.When using window-opening ventilation to control CO_(2),it is necessary to ensure sufficient window opening time.The mechanical ventilation system with a filtering device can control the indoor PM_(2.5) concentration far below the limit value in haze weather.The six mechanical ventilation modes tested all can not control the indoor CO_(2) concentration within the limit,and the main reason is the improper air distribution design.The simulation and optimization results show that the best air distribution design is to set the side air supply inlet at the diagonal direction of the bottom exhaust door slot.