The Piston Action Wind And The Subway Energy Saving

The piston wind has close relationship with the subway ventilation and the energy consumption. With the metro development, the deeply researches on the regularity of the piston wind is of the theoretical and practical value. The effects on the temperature and velocity fields of the tunnel and station from the piston wind are emphatically analyzed. Study the factors related to the piston wind and compare the energy consumption under different conditions.Several methods are adopted in this paper together, such as theory analyses, model experiment, field test and numerical simulation. To imitate the subway tunnel, the model experiment focus on the tunnel piston wind's characters and the influencing factors, taking the descending object as the impetus. The field tests include the temperature and velocity variation of the platform, the underground hall, the stair, the passageway under different seasons, time, and train conditions. The numerical simulation is based on the SES (Subway Environment Simulation). The mechanism analyses are composed of one dimensional steady and unsteady flow theory, Couette turbulent theory and three dimensional unsteady compressible flow's assumption.Through the research, three parts conclusions are deduced. Fist, the temperature and velocity characters of the subway tunnel, air shaft and wind road roundabout influenced by the piston wind under different time, train position. Secondly, the piston wind affects' regularity on the platform, the underground hall, the stair and the passageway with various time and train conditions. Thirdly, analyze the factors which have influence on the piston wind character through sole variation experiment and compare the influencing degree through orthogonal experiments. The energy consumption of different conditions is computed and compared. These results provide reference for the subway design and operating. Taking use of the piston wind reasonably is one of basic keys to realize the metro energy saving.