Research On The Thermal Environment Investigation Of The Nanjing Subway Carriage In Summer And The Thermal Comfort Modeling Research Of The Occupants

With the improvement of urbanization level in China,the subway is becoming the preferred means of transportation for urban residents.As a distribution center for passengers,the space of subway cars is relatively closed,and the personnel clustering coefficient is high.The thermal and comfortable environment in subway cars is increasingly receiving widespread attention.This paper takes the thermal comfort environment and passengers in Nanjing subway cars in summer as the research object,uses a questionnaire and on-site measurement of thermal environment to establish a thermal comfort model based on subway cars,and introduces a two-node model based on human physiology to predict human body temperature The main work and research results are as follows:(1)Use subjective questionnaire survey and objective thermal environment field test methods to investigate the air temperature,black ball temperature,relative humidity,wind speed,pressure and other conditions in subway cars,and understand the thermal environment conditions of different lines and the overall subway cars,and analyze subway The thermal comfort of the passengers in the cabin reflects the situation.(2)The commercial software is used to analyze the hot and humid environmental factors in the subway car,and the passenger's subjective votes on the hot and humid environment in the subway car are counted.The relationship between environmental factors such as air temperature,relative humidity,wind speed and carbon dioxide and the thermal comfort of the human body are discussed.(3)Extensive collection and arrangement of common thermal comfort evaluation models,analysis and classification of the collected thermal comfort models,and summarizing the regularity of the existing thermal comfort models.The measured and surveyed data are compared with existing thermal comfort models,their adaptability to the thermal comfort of subway passenger environment passengers is evaluated,and the necessity of re-modeling the subway environmental thermal comfort model is analyzed.(4)Summarize the correction criteria for modeling the thermal comfort model,and determine the pending form of the thermal comfort model based on the modeling revision criteria and the conclusions of the adaptive analysis of the existing thermal comfort model.A new,more accurate thermal comfort model for the Nanjing subway car in summer is obtained with a simpler formula structure.(5)The thermal response of an individual occupant in a Nanjing subway car under transient conditions is discussed.The finite difference method is used to discretize the non-linear ordinary differential equations of human skin temperature tsk and core temperature tcr in time units,and its numerical solution is obtained by iterative software programming.Finally,the effects of changes in human characteristics and cabin thermal environment parameters on human thermal response over time are analyzed.The research in this paper can provide useful reference for the study of thermal environment and human thermal comfort in similar fields.