Improvement Of Ventilation Of Inner Corridor Classroom By Horizontal Natural-vent Channel

Classroom is the main study and work place for students and teachers.Students spend most of their time in the classroom,so the air quality in the classroom has attracted more and more researchers’attention.Especially with the global outbreak of the new coronavirus in 2020,students’resumption of classes has significantly increased the indoor ventilation requirements of classrooms.The inner corridor type linear teaching building is one of the main layout forms of teaching buildings because of its reduced footprint and compact functions.However,in this type of teaching building,because the corridor is inside,the depth is too large,which hinders the natural ventilation of the classroom to a certain extent,especially the ventilation effect of the classroom on the leeward side.In order to solve this problem,this paper proposes to set up a horizontal airflow channel on the ceiling of the classroom,and convert the original unilateral ventilation of the classroom in the inner corridor into the ventilation through the hall,so as to achieve the purpose of enhancing the ventilation effect.This paper uses on-site measurement,numerical simulation,wind tunnel experiment and other methods to study the improvement effect of airflow channel on classroom ventilation in the inner corridor.First,in order to explore the current situation of classrooms with inner corridors,a classroom temperature field measurement was carried out in a classroom in the teaching building of inner corridors in Xiangtan City,Hunan Province.Four monitoring points were set up in the classroom to analyze the temperature changes in the classroom from 9:00 to 11:40.The results show that classrooms with unilateral ventilation require more natural ventilation to meet the thermal comfort needs of students in the classroom.Then,the Computational Fluid Dynamics（CFD）simulation results were strictly compared with the wind tunnel experimental data to verify the wind pressure reliability of the numerical simulation in single-side double-opening,opposite-side double-opening and thermal pressure simulation.accuracy.It lays the foundation for the next ventilation simulation analysis of the interior corridor classroom building.Then,taking the classroom measured on site as a prototype,a basic model unit was abstracted,and CFD was used to simulate the change of ventilation volume of the classroom in the inner corridor under different wind direction angles and wind speeds after closing the inner doors and windows,and after setting the air passages with different cross-sectional areas.Ventilation changes.The simulation results show that the total ventilation volume of the classroom with a 5.4m² cross-sectional area airflow channel increases by 731%compared to the total ventilation volume without airflow channel,3.6m² increases by 490%,and 1.8m²increases by 248%.It can be seen that the horizontal airflow channel of the ceiling has a significant potential to improve the ventilation volume of the classrooms of the inner corridor type linear teaching building.Finally,the changes of airflow organization,temperature and CO₂ concentration in the classroom after setting the airflow channel were discussed.The results showed that the airflow channel can effectively reduce the temperature in the classroom,improve the thermal comfort,and at the same time reduce the CO₂ concentration and improve the air quality.The horizontal natural ventilation channel technology proposed in this paper provides a new way of thinking for the improvement of ventilation design of buildings with large interior corridors.