Air Quality Control In Classrooms Of Elementary And Secondary School Under Haze

In recent years,haze weather frequently occurs,resulting in an increase in indoor PM2.5concentrations.The classroom is a daily learning place for primary and middle school students,and the air quality in the classroom is particularly important for students who are in a period of growth and development.Primary and middle school classrooms in the northern regions mostly use centralized heating,and personnel are concentrated.When the haze weather is severe,the classroom will be closed for a long time,and the concentration of CO₂ produced by the people’s breathing will lead to a decrease in learning efficiency.Fresh air need to be introduced to dilute the CO₂,the introduction of which will increase the PM2.5 in the classroom.In order to solve the problem,this paper studies the law of the variation of indoor CO₂ and PM2.5 concentration with the method of field tests and theoretical simulations,and also proposes measures to improve air quality in classrooms for elementary and middle schools under hazy weather,providing a theoretical basis for designing fresh air systems in classrooms for primary and secondary schools.First of all,the research results in related fields at home and abroad were reviewed in this paper.The influencing factors of air quality in the classroom and the sources and hazards of major pollutants in the classroom were analyzed,and the main contaminants in classroom under haze were identified.Secondly,based on the investigation and site tests of a middle school classroom in Jinan,variation of indoor CO₂ and PM2.5 concentration was discussed,the subjective influence of CO₂ concentration on students’learning efficiency was studied.Then,according to China’s current standards and relevant regulations,CO₂ concentration and PM2.5 concentration was adopted as the benchmark to determine the amount of fresh air in the classroom.The method of calculating the fresh air volume was determined to satisfy CO₂and PM2.5 standards simultaneously.And indoor air quality control methods were proposed.At last,Airpak software was used to build classroom models based on research classrooms,the Gambit software was applied to mesh the model.And by selecting the K-εtwo-equation model as the turbulence model,the law of the distribution of indoor temperature,humidity,carbon dioxide concentration and PM2.5 concentration under various working conditions were simulated in the paper.Among the seven simulated tuyere locations,the optimal air flow organization and the fresh air supply temperature to meet the indoor comfort requirements were given.