中文摘要：

基于浓度守恒原理建立了一次回风空调系统室内PM_（2.5）浓度模型,研究了过滤器分别安装在新风段、回风段和送风段时过滤效率和新风量的变化对室内PM_（2.5）浓度的影响。模拟结果表明：在室外PM_（2.5）浓度大于室内初始值的条件下,过滤器安装在送风段或回风段时,减少新风有利于室内PM_（2.5）污染控制,过滤器安装在新风段时,根据过滤器效率调节新风,过滤效率小于临界效率,减小新风有利于室内污染控制;在室外PM_（2.5）浓度小于室内初始值的条件下,过滤器安装在送风段或新风段时,增加新风有利于室内PM_（2.5）污染控制,过滤器安装在回风段时,也存在临界效率,过滤效率小于临界值,增加新风有利于室内PM_（2.5）污染控制。

英文摘要：

An indoor PM_（2.5）concentration model of a primary return air system is presented based on a balance of concentration. The variation in filter efficiency and outdoor air rate on indoor PM_（2.5）concentration is discussed,with filters installed outdoors at the return and supply vents. The simulation results show that if the outdoor PM_（2.5）concentration is higher than the initial indoor value,it is recommended to reduce the amount of outdoor air when filter was installed at the supply or return vent to control the indoor PM_（2.5）concentration. In addition,when a filter was installed for the outdoor airstream,the outdoor air rate had to be adjusted according to the filer efficiency,such as decreasing the outdoor air rate if the efficiency was greater than the critical value. If the outdoor PM_（2.5）concentration was lower than the initial indoor value,it was recommended to increase the amount of outdoor air when a filter was installed at the supply or outdoor vents. When a filter was installed at the indoor vent,it was advised to increase the outdoor air rate if the efficiency was lower than the critical value.