Numerical Calculation Of Subway Piston Wind And Energy-saving Research Of Ventilation

Nowadays, the subway construction has entered into a rapid development phase, and environmental control system is much more concerned due to high energy consumption. At present, there are two main forms of environmental control system design which are exit system and platform screen doors system. However, they both have shortcomings to some extent. Therefore, this paper presents a new platform door system that can achieve a higher energy saving which is to install additional control tuyere on the PSD system. In winter(summer), close the tuyere to prevent incoming of cold(hot) air into the station from tunnel, as a result, this could reduce the station's hot(cold) load. That is to say, the new system is more energy-saving than the exit system. During the transition seasons, close the air-conditioning system and open the control tuyere to let the piston wind blow into the station and take away partial load so as to create a more comfortable moment for the passengers.In this paper, firstly, I research the features and natures of the piston wind by using the theoretical knowledge and numerical simulation. I use the piston wind velocity as the boundary condition which is generated by different train speeds, while the boundary condition is imported by using UDF function in C computer language. Moreover, I was able to calculate the design temperature and humidity index in Nanj ing's subway station by adopting a new comfort indicator——RWI (relative warm index), and prove its reasonability. The station's design temperature and humidity index determined by RWI could not only meet the comfort requirements of passengers, but also reduce the air-conditioning load and save initial investment and operation costs.Finally, I proposed three design options of control tuyere and did numerical calculation of these three design options respectively. In the end, I worked out the best option by doing comparison and analysis of two aspects in terms of ventilation and energy efficiency of these three design options. Basing on this best option of control tuyere, I implemented a certain detailed analysis of indoor stations'velocity and temperature fields when the train coming into the stations, and further proved the best design option could achieved the people's comfort requirements.