基于室内CO_2浓度标准值的临界新风量研究

Study on the critical outdoor air velocity based on the standard of indoor CO_2 concentration

目的探讨满足室内CO_2浓度标准值实际所需要的最小通风量,即临界新风量;为室内通风量的设计和改善室内空气质量提供依据。方法对不同新风量和室内人数条件下某室内空间(体积V0=37.5 m^3)的CO_2浓度进行监测并对其变化趋势进行拟合。结果室内CO_2实测浓度变化符合y=b+ae-kt型指数曲线。在门窗紧闭的条件下,对不同新风量时室内CO_2实测值进行y=b+ae-kt型指数曲线拟合,可得出自然渗透风量V1=11.5 m^3/h,新风系统风量V3=60 m^3/h时的有效新风量V2=20.1 m^3/h;本实验条件下的新风系统通风效率E只有34%。该室内空间所需要的临界新风量(满足CO_2标准限值1 000 ml/m^3要求所需要的最小新风量)V4=74n-32(n:室内人数)。结论新风系统能够有效控制室内CO_2浓度,临界新风量与室内人员数量呈线性相关。

Objective To make certain the actual minimum ventilation rate need for meeting the standard of indoor CO2 concentration,and to provides the basis for the design of indoor ventilation rate and improving indoor air quality. Methods The CO2 concentration of indoor space（volume： V0= 37.5 m3） was monitored,and its changing trend was fitted under different indoor conditions including fresh air volume and indoor personnel quantity. Results Fitting results showed that the indoor CO2 concentration changed in accordance with index curve, y=b＋ae-kt. Under the condition of the office doors and windows closing,indoor CO2 values measured was fitted based on index curve（y=b＋ae-kt） under different fresh air volumes respectively,which were extimated as V1=11.5 m3/h for the natural permeability air volume,V2=20.1 m3/h for the effective air volume based on air volume of fresh air system（V3=60 m3/h）. The ventilation efficiency（E） of the fresh air system was only 34% under the condition of this experiment. The indoor space required for the critical fresh air volume [the least new air volume needed for meeting the requirements of the CO2 standard limit（1 000 ml/m3）] was V4= 74 n- 32（n： indoor personnel quantity）. Conclusion Outdoor air system can control the indoor CO2 concentration effectively,the critical outdoor air velocity presents linear correlation with indoor personnel quantity.