Influence of air distribution modes in civil air defense basement on carbon dioxide concentration distribution in wartime

Abstract

In order to protect the living environment and effectively control the harmful gas composition in the basement of civil air defense in wartime, this paper studies the pollutants of a civil air defense basement project in Jinan by CFD numerical simulation technology, and simulates the CO2 concentration distribution under three different air distribution forms in civil air defense. The results show that when the second-class shelter reaches the high-density population environment, the air conditions under the distribution form of side air supply and upper air return of the building meet the living conditions of the shelter personnel. The average CO2 concentration is 7200 ppm, but the central area forms a pollutant concentration area with an area of about 14.3%, and the highest concentration is 17000 ppm, which affects the physiological function of the shelter personnel. The CO2 concentration distribution simulated by the air distribution modes of upper air supply, side air return and upper air supply, lower air return is more uniform, and the average pollutant concentration is 6000 ppm and 5500 ppm. The air distribution effect of upper air supply and lower air return is the best, where the CO2 concentration is 23.6% lower than that of side air supply and upper air return scheme and 8.3% lower than that of upper air supply, side air return outlet scheme. The CO2 concentration distribution is uniform and there is no pollutant aggregation point. Under the special conditions of wartime, the air distribution of upper air supply and lower air return with uniform air outlet layout is more conducive to pollutant control.