Research On The Thermal Environment Comfort Evaluation And Optimization Design Of A University Campus In Northern China

Under the background of continuous urban development and lack of attention to outdoor space,the urban microclimate gradually deteriorates and the comfort of the outdoor thermal environment decreases.The campus has a high density of personnel and complex activities,and the comfort of its outdoor environment directly affects the daily activities and teaching activities of teachers and students.Therefore,this thesis takes a university campus in the north as the research object,and analyzes the outdoor thermal environment and student comfort of the university campus under high temperature through field tests and questionnaires.At the same time,a three-dimensional building model of the campus is constructed.The planning and design elements are used to simulate the outdoor thermal environment,and the optimal design method of the outdoor thermal environment is obtained.The main research contents are as follows:First,the research status of outdoor thermal environment at home and abroad is reviewed.The research on the outdoor thermal environment mainly uses the methods of experiment and simulation to evaluate the characteristics and influencing factors of the thermal environment in a certain area,and propose improvement methods for the problems found.Based on the review,the research puts forward the design elements commonly used in urban planning and design,such as building height,street aspect ratio,sky viewing angle coefficient,and floor area ratio.Combined with the existing outdoor thermal environment evaluation methods,the campus microclimate and Thermal comfort evaluation index.Secondly,take a university in Jinan as an example to conduct field research.The research is divided into two stages.The first stage is carried out in high temperature and low humidity weather.The campus is divided into outdoor activity areas,teaching areas,green areas and living areas.Through field tests and questionnaires,the thermal environment of the areas where students often play is tested.characteristics,to investigate students’ thermal comfort evaluation of the campus environment.The outdoor thermal environment needs of different areas were obtained,and the study found that more than 60% of students in each area felt comfortable.Among them,the thermal comfort of the teaching area is the worst,and students have a strong demand for improvement,so the second stage of testing is carried out in the teaching area.In the second stage,the summer with high temperature and humidity was chosen,and 10 measuring points were arranged around the teaching building where students often move.The test found that,except for a few areas under the shade of trees,the thermal environment was poor in other areas.Therefore,the study optimizes the design of the outdoor thermal environment of the campus from three aspects: increasing greening,improving the building layout and increasing the albedo of the underlying surface material.Then,using ENVI-met 4.4.5 software,according to the actual situation of the campus,a campus model including buildings,vegetation,roads and water bodies is established.The accuracy of the model is verified by the second-stage test,and the results show that ENVI-met4.4.5 can be used as a prediction tool for outdoor thermal environment in cold regions.Therefore,the improvement effect of 19 optimized working conditions on the outdoor thermal environment is simulated.Finally,based on the simulation results of the above working conditions,the thermal environment evaluation index is used to analyze the influence of different design elements on the thermal environment.According to the influence of vegetation greening on the thermal environment,it is concluded that increasing the greening rate,especially planting tall trees,is beneficial to the improvement of the outdoor thermal environment.The improvement of outdoor thermal comfort has the greatest impact;according to the impact of the underlying surface material on the thermal environment,it is concluded that the use of a high albedo underlying surface reduces the air temperature,but increases the solar radiation,which reduces the outdoor thermal comfort.With the increase of the surface albedo,this phenomenon is more obvious.In view of the influence of the building layout on the thermal environment,it is found that adding a building within a reasonable volume ratio can effectively improve the outdoor thermal environment due to the reduction of the sky viewing angle coefficient.As the height of the building increases,the degree of improving the microclimate gradually decreases.