Study On The Thermal Comfort Of Atrium Space In University Libraries In Severe Cold Area Of Xinjiang In Summer

Library is one of the most important functional buildings in Colleges and universities.Daily readers stay here for a long time with a large number of people.Atrium space is the core of Library building,and the external environment has a certain impact on it.Designers often pay more attention to their unique space feeling and lighting characteristics in concrete design,but neglect the people-oriented design concept,which makes the thermal comfort of atrium space directly affect the normal experience of indoor staff.In the summer of severe cold regions in Xinjiang,the adjustment of indoor environment only by mechanical equipment not only increases the operation cost and energy consumption,but also greatly reduces the thermal sensation of human body compared with the self-regulation function of making full use of atrium space.Therefore,it is particularly necessary to study the thermal comfort of atrium space in University Libraries in Xinjiang cold region.Based on the unique climate environment in Xinjiang,this paper studies the factors affecting the thermal comfort of the atrium space of University Libraries in summer by means of questionnaires,field measurements and CFD simulation,and integrates the architectural design strategies suitable for library buildings in this area.Firstly,through the analysis of meteorological data and software,this paper demonstrates the demand of natural ventilation in summer for University Libraries in severe cold regions of Xinjiang.Through the analysis of the space layout,practical function,form and volume of atrium,many analysis elements are provided for CFD simulation research.CFD simulation software is used to simulate and analyze the proportion of atrium,the shape of atrium section and the shape of top exhaust outlet,which can more truly reflect the rules of summer ventilation and thermal comfort of atrium space in University Libraries in severe cold regions of Xinjiang.The conclusions drawn in this paper are as follows:1.Compared with no natural ventilation,the indoor thermal comfort satisfaction in June,July and August can be increased by more than 30% under natural ventilation in severe cold regions of Xinjiang,and the thermal comfort areas have been expanded in almost all periods of the above three months.2.Under the comprehensive comparison of equal building area,rectangular atrium is better than square atrium in ventilation effect,simple construction,strong indoor space directivity,more suitable for the layout of Library buildings,more conducive to intuitive simulation and comparison.3.Through the simulation of the proportion of the atrium,it is concluded that the average wind speed of each proportion of the atrium increases by 0.1m/s in turn as the proportion of the atrium increases by 5%.At the same time,with the decrease of PAR value,the natural ventilation and comfort in the library room are further improved.4.Compared with the shape of atrium profile,the overall thermal comfort of type A atrium is the best.The former has an average wind speed of 0.78m/s and a PMV mean of-0.64,while the latter has an average wind speed of 0.77m/s and a PMV mean of-0.63.The overall comfort of HA atrium is the worst,PMV is only-0.31,the other atriums are normal,the average wind speed is about 0.55m/s,PMV is about-0.46.5.As for the top interface height,the 27.8m exhaust outlet height is better and the PMV average value is-0.63.Continuing to increase its height has a greater impact on the comfort of the upper part of the atrium,but the impact on the lower part is not obvious and will affect the overall volume of the building.6.Through the comparative analysis of the top exhaust outlet,it is concluded that the change of the top exhaust outlet shape has little effect on the overall environment of the indoor atrium space,and the V-shaped exhaust outlet performs better in ventilation and exhaust performance,and the PMV of the whole atrium is-0.66.The overall improvement effect of parallel exhaust outlet is not obvious,the overall wind speed is weakened by 41.4%,and the overall PMV increased by 18.9%.7.Through the analysis of Shihezi University Library as an example,the optimized strategy has improved the Shihezi University Library,and the overall PMV index has decreased from 1.18 to nearly 70% to 0.36,which proves that the optimized strategy has a positive effect.