Piston Effect On The Subway Station And Its' Utilization In The North Of China

The influence of piston effect on the subway station through tunnel and passageway is one of the main fator in energy consumption of the subway. It is a potential measurement for energy saving to make use of the piston wind in transition season and in winter. Compared with the traditional platform doors, there are many advantages for the platform screen door with vents, because it can make use of piston effect for ventilation and also can assure the safety and comfort. Based on measurements on site, three mean areas are investigates, i.e., the effect of piston wind on subway station, the effect of piston wind on energy consumption of subway and applicability of the platform screen door with vents in north cities in China.The influence of the train-induced air on subway station and the comfort level of subway station in dynamic and transient conditions are analysized based on experimental data. The comfort level, content of inspiratory particles and noise level show that the environment of subway station with automatic platform gates can satisfy the requirement of the standard.The subway station is considered as basement to carry out the energy simulation using the program: EnergyPlus. Energy consumption of platform screen doors system, automatic platform gates system and platform screen doors with vents system is analysized using typical year weather data based on comprehensive load analysis. The accuracy and convenience of the program applied to subway station is improved by setting parameters and selecting modules in reason.Technology economic analysis is carried out to compare the platform screen door with vents with the traditional platform doors using annual cost method and value engineering. The results show that the automatic platform gates system is better than the platform screen doors system if considering the primary invests and operating cost, which provide design guidelines for engineering applications.In order to study the temperature and velocity fluctuation exactly, a CFD (computational fluid dynamics) unsteady model with a piecewise function as boundary conditions are built to simulate piston effect, which is different to former researches. It is a simple method to acquire more exactly data than steady model, so that a complete effective research method is developed for the numerical simulation study of piston effect and subway ventilation and air conditioning system. A new kind platform door called platform screen door with vents is put forward. Controllable vents are added to the door, which is closed in summer to provent the heat generated by the train and is open in other seasons to untilize piston effect for ventilation. At fire condition the vents will be open to help exhausting smoke and to buy time for evacuate the subway station. The platform screen doors with vents system combines the advantages of platform screen doors system and automatic platform gates system, so that it is a more safe, more comfortable and energy saving platform doors system for north cities and it provide a new technology for improving on platform doors system and for energy saving in subway ventilation and air conditioning system.