Research On The Spatiotemporal Characteristics Of Anthropogenic Heat In A University In Chongqing

With the rapid development of urbanization,the anthropogenic heat generated by human activities has also increased its impact on the urban thermal environment,which is one of the important factors that intensifies the urban heat island effect.The university campus is considered to be a miniature city,where the personnel density is high and the activities are complex.The thermal environment status directly affects the students' physical and mental health.In the current research on outdoor thermal environment,the influence factor of anthropogenic heat has not been paid attention to,resulting in large differences in the prediction and evaluation of outdoor thermal environment.Therefore,this dissertation carried out a detailed study on the time variation and spatial distribution characteristics of anthropogenic heat sources in a university campus in Chongqing in order to truly reflect the influence of anthropogenic heat emissions on the regional thermal environment.Firstly,based on the analysis of theories related to urban surface energy balance,the relationship between urban heat budget balances is explained and the theoretical basis for the research of human heat is laid.Questionnaire and field surveys were used to statistically analyze the distribution characteristics of students on campus,and combined with the metabolic calculation method of the human body to obtain the spatiotemporal characteristics of the body's metabolic heat release.Secondly,the main roads to be studied are identified through on-site investigation of road conditions on campus.Based on the actual conditions of motor vehicles on campus,video traffic data collection technology is used to statistics on the traffic volume of various types of vehicles on a time-by-hour basis.Based on the fuel consumption calculation of heat of different types of motor vehicles and get the spatiotemporal distribution characteristics of traffic heat release.The results of the study indicate that the traffic heat release exist the daily changes characteristics of the “double peak” phenomenon on both the working day and the non-working day.The time of occurrence is in the morning from 8:00 to 9:00 and in the afternoon from 16:00 to 18:00.This has a lot to do with the commute time of teachers and staff,and the spatial distribution is also non-uniform due to the school traffic control.Thirdly,with the use of DesignBuilderV5.0 energy simulation software,a threedimensional model of actual size is built for a typical building,with the actual envelope parameters,working time,and meteorological parameters as the initial conditions for the simulation,and based on energy consumption verification,hourly energy consumption simulations were conducted to obtain the spatiotemporal variation characteristics of typical building anthropogenic heat.Finally,the results were extended to other buildings of the same type on campus to obtain the characteristics of anthropogenic heat of campus buildings.Finally,the characteristics of the spatial and temporal variation of the total anthropogenic heat in the campus are analyzed and illustrated.And compared with the solar radiation,to assess its impact on the city's energy balance.The results show that in the winter conditions,the total anthropogenic heat on working days and non-working days is 38.2% and 35.3% of the solar radiation,respectively;in the summer conditions,the total anthropogenic heat on working days and non-working days is 15.8% and 17.1% of solar radiation,respectively.In conclusion,this research analyzes the spatiotemporal characteristics of anthropogenic heat from different sources using survey questionnaires,video data acquisition techniques,and energy consumption simulations.The research results are expected to provide strong support for improving the accuracy of climate models and environmental effects studies,especially numerical simulations.