METHOD OF COMPENSATION THE INFLUENCE OF THE PISTON EFFECT IN THE VENTILATION SYSTEM OF SUBWAY AND THE DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2018 - IPC E21F1/00 

FIELD: instrumentation; ventilation.

SUBSTANCE: proposed group of inventions relates to a method and device for compensating for effect of piston effect in subway air ventilation system. Method includes changing the tunnel’s open flow area to change the aerodynamic resistance of air path in station vicinity due to the arrangement of expansion tanks of estimated size, adjacent to the station platform on both sides, connecting the first and second paths of the main line tunnel, and performing the formation of turbulent state of the air flow in the allocated area of the air path at the length Lp of the main line tunnel, that provides a reduction in the speed of the air flow pushed by train leaving the main line tunnel, with V_x1 up to V_x2, where V_x1 (m/s) – the speed of turbulent air flow during constrained movement of train along the tunnel, V_x2 – the speed of turbulent airflow after the expiration of air into the expansion tank. Device contains two expansion tanks created at the junction of the main line tunnel to the station platform, on both sides of the platform, forming a free additional space that alters the aerodynamic resistance of the air path near the station platform. Size of the expansion tanks are determined from the conditions of abutting the tank to the station and the train’s size and have height H_p = f (H_t) and width B_R = B_t, length of the expansion tank L_p calculated on the basis of the L_p= f (V₀, δ, Δ), where V₀ – speed of the train, δ – gap between the walls of the tunnel and the train, Δ – Roughness of tunnel walls, N_t – height of the main line tunnel, V_t – width of the platform hall.

EFFECT: technical result consists in reducing the number of circulation flows, reducing the speed of air coming from the tunnel to the platform, as the train approaches the station, providing the normative parameters of the microclimate at the station and in the metro vestibule.

2 cl, 2 dwg