Effects of Air Supply Modes on Ventilation and Respiratory Pollutant Dispersion Characteristics of High-Speed Trains
High-speed trains carry a large number of passengers and have a well-developed transportation network.However,the closed compartment environment is likely to cause the accumulation of pollutants.In order to improve the comfort and safety of the train,a full-scale compartment ventilation model of the train under full load conditions was established based on computational fluid dynamics(CFD).For the exhaust mode where the exhaust vent was located above the window,the coefficients of velocity non-uniformity,temperature non-uniformity,and energy utilization,as well as ventilation efficiency were used as the evaluation indexes of the train's ventilation system.The effects of six air supply modes on the flow field characteristics and diffusion characteristics of respiratory pollutants in the compartment were comparatively studied,including perforated ceiling air supply,lower air supply,perforated ceiling air supply combined with lower air supply,local perforated ceiling air supply,side roof air supply,and local perforated ceiling air supply combined with side roof air supply.The results show that by adjusting the flow distribution ratio between the air vents,the air supply can flow evenly to both sides of the passenger compartment,thereby improving the temperature uniformity in the train.When the lower air supply is used,it helps to improve the energy utilization coefficient and ventilation efficiency of the ventilation system,which are as high as 1.38 and 1.21,respectively.However,it will deteriorate the riding comfort of the train.By studying the interaction of respiratory pollutants among passengers,it is found that the respiratory pollutants of passengers in column C tend to diffuse to the breathing area of passengers in column B,thereby aggravating cross-infection among passengers.Reducing the size of the air supply outlet of the perforated ceiling and using local perforated ceiling air supply mode can effectively alleviate this phenomenon and reduce the volumetric concentration of pollutants to 0.0019.
万方数据
维普
