Study on ventilation and heating forms of underground cavern and energy saving measures under extremely cold conditions

Abstract

A large underground cavern project is located in a severely cold area, with a winter period of 208 days, an average temperature of-19.7 ℃, and a minimum temperature of-45.4 ℃. The distribution of this cavern is complex and intricate, with a long construction period for the main cavern and multiple intersections of construction tunnels and water curtain tunnels. With the progress of construction, the connection mode, ventilation channels, ventilation distance, and ventilation circuit between tunnels are constantly changing. In response to the difficulties encountered during the construction process mentioned above, we adopted the Computational Fluid Dynamics(CFD) theoretical model to simulate the airflow and temperature fields of the water sealed cavern during different construction periods. We corrected the simulation result through on-site data collection, striving to guide the construction through computational simulation. We have utilized the result of computational simulation to optimize and adjust the ventilation and heating layout during winter construction, ensuring that the ambient temperature inside the tunnel remains above 5 ℃ under extreme cold conditions. At the same time, we have fully utilized the residual heat of the gas discharged from the tunnel to solve the problem of road icing in the traffic tunnel, providing a good guarantee for the advancement of engineering construction.

Keywords

cold conditions / underground cavity / improve air circulation / heating / energy saving / freezing / CFD