Studies On The Coupling Influence Of The Pistons Wind And Mechanical Ventilation On Thermal Environment Of The Platform Of A Subway Station

With the subway network booming in recent years,more attention should be pay attention to maintain a thermal comfort environment of subway station by less energy consumption,as it is a distributing center of a large number of passengers.Nowadays, platform screen door system is widely used in the design of environmental control system.However its initial cost is high and its control system is complicated.It still need further investigation on its economy and applicability.To this end,this study aims at providing more choices for the of environmental control system design in Xian by exploring the applicability of open system.Through in-site survey and measurement,a new method to determine the hourly control temperature of the underground hall and platform of a subway station was proposed by specifying reasonable Relative Warmth Index difference and using local hourly outdoor temperature.It can help to meet passengers' needs for temporary thermal comfort.Based on the obtained control temperature,the cooling loads of public areas of a subway station were calculated for peak time and off-peak time.And the supply air flow-rate and fan operational modes were determined.Then,a typical island platform of subway station,which is being under construction in Xian,was chosen as the prototype for simulation studies.Thermal environment of the platform were simulated under four cases,that is,peak time,a train parking;off-peak time,a train parking;peak time,two trains parking;off-peak time, two trains parking.Analysis on temperature and velocity filed of the platform,which is the coupling effect of piston wind and mechanical ventilation,indicates that using the closed-open environmental control system in Xian can produce feasible and comfortable platform environment.Finally,the influence of supply airflow rate on was also explored.