Measurement And Simulation Analysis Of Thermal Environment Of A Shallow Underground Building

In order to realize the sustainable development of cities and the rational utilization of resources,accelerating the development of underground space has become an inevitable choice for cities to solve the problem of urban congestion.Therefore,underground buildings such as subways,underground walkways,and underground shopping malls have emerged in large numbers,and with the improvement of people’s living standards,the internal thermal environment of underground buildings has gradually been paid attention to.At present,domestic and foreign scholars’ research on the thermal environment of shallow underground buildings is mainly focused on underground buildings with large population bases and high mobility,such as underground shopping malls,underground supermarkets,and subways,while there is little research on underground office buildings.Therefore,it is necessary to study the thermal environment of shallow underground office buildings.This thesis took a duplex-type shallow underground office building in Wuhan as the research object,and conducted a one-year test on the field measurement method.According to the different research objects,the whole experiment was divided into the overall thermal environment measurement(the whole shallow underground building was the research object)and the thermal environment measurement of a single room(a certain room was the research object).The overall measured experimental results showed that the shallow underground buildings had the characteristics of warm in winter and cool in summer and high humidity in summer.In the short term,unlike the large changes in the temperature and humidity of the ground outdoor air,the indoor thermal environment of shallow underground buildings was relatively stable,and the temperature and humidity were evenly distributed,which was less affected by the temperature and humidity of the ground outdoor air.However,in the long term,the air temperature and humidity in the shallow underground building would increase with the increase of outdoor air temperature and humidity on the ground,and decrease with the decrease of outdoor air temperature and humidity on the ground,showing a trend of synchronous change.The air humidity in shallow underground buildings in hot summer and cold winter regions showed the highest relative humidity throughout the year in July and the lowest relative humidity throughout the year in December.In summer,the relative humidity of air in shallow underground buildings was too high,which was basically above 80%.The relative humidity of shallow underground buildings in other seasons was more suitable.When the shallow underground building was ventilated in summer,in addition to providing the necessary amount of fresh air for personnel,it was also necessary to dehumidify the air in the underground buildings.When the shallow underground building was ventilated in spring and autumn,it was mainly to provide the new air volume necessary for personnel activities.When the shallow underground building was ventilated in winter,in addition to providing the necessary fresh air volume for personnel activities,it was necessary to heat the fresh air appropriately to make the indoor temperature in a relatively suitable range.The measured results of a single room showed that the air temperature in the shallow underground room was suitable,but the relative humidity was too high;when the left window was opened,the room ventilation effect was slightly better than when the right window was opened;the existing mechanical exhaust system could meet the needs of personnel for fresh air,but It couldn’t solve the problem of high air humidity in the room.In order to further analyze the characteristics of the internal thermal environment of the shallow underground office building,based on the field measured data,the thermal environment of the entire shallow underground building and a single underground room were simulated with CFD software.The overall simulation results showed that the air relative humidity in the shallow underground building was too high,the longer the ventilation corridor in the underground building was,the worse the ventilation effect would be,and the more curved the ventilation corridor was,the worse the ventilation effect would be.The simulation results of a single room showed that the air humidity in the underground office room was too high and the air velocity was too large.By changing the entrance position of shallow underground building,changing the curved passage to the straight passage and changing the horizontal sliding window to a casement window,we can better solve the problem of high relative humidity and large air velocity in the shallow underground building,and provide a more comfortable thermal environment for people working in the shallow underground office room.