Study On Thermal Environment Of Subway Car In Dense Crowd

With the population growth and the expansion of the city scale,the passenger flow of subways in various cities is gradually increasing,and personnel intensive will become a normal state of subway cars.The increase in passenger capacity will have a series of effects on the environment of the subway car,such as changes in ambient temperature and humidity,poor air mobility,and excessive pollutant concentrations.The change of thermal environment has a direct impact on the passenger’s thermal comfort.Under the condition of dense population,the thermal environment of the subway car has a certain guiding role in improving the passenger environment and improving the passenger’s thermal comfort level.In this paper,the combination of model experiments,numerical simulations,field tests and questionnaires is used to study the thermal environment of subway cars under dense population conditions.The main work is as follows:Through the questionnaire,the thermal environment of subway cars under different density of Shenyang,Beijing,Shanghai and Guangzhou was evaluated.The influence of the density of passengers in the cabin on the passenger’s thermal sensation was analyzed.Based on the theory of human body heat dissipation and dehumidification,combined with model experiments and CFD simulation,the research on the heat dissipation characteristics of human body under mutual interference conditions shows that the changes of surrounding people will change the heat dissipation characteristics of the human body.It lays the foundation for the simulation of the thermal environment of the subway car in the dense crowd.Based on the Qingdao Metro,the numerical simulation of the cabin thermal environment under different seat density conditions was carried out to analyze the changes of temperature field,velocity field,human body surface temperature and human body heat dissipation under different passenger densities.On-site measurement and questionnaire survey were conducted on each line of Qingdao Metro,and the thermal environment of the cabin and the passenger’s thermal sensation under the operating conditions were analyzed.The thermal environment changes of the passenger compartment and the passenger’s thermal sensation were obtained under different passenger densities,and the passengers’ thermal sensation was carried out.Evaluation.The research results of the project can provide reference for the design and operation adjustment of the vehicle air conditioning system.