Modeling of tunnel air condition in the Kyiv (Ukraine) subway to reduce humidity

Experimental study of the level of relative humidity of tunnel air in the Kyiv subway in recent years has shown a constant exceeding of the normalized value (established by regulations) of relative humidity of tunnel air (>75 %) during the summer period, which led to the deterioration of equipment and the rims of the tunnel walls. Comparison of absolute humidity values of tunnel air and supply air from ventilation shafts from the environment under the current tunnel ventilation modes led to the recommendation to change these modes from removal to injection of air with lower absolute humidity than in the problem tunnels. This idea was verified and validated using 3D modeling of the thermo‐gas‐dynamic and humidity conditions of the tunnels over 3 calendar years, resulting in a decrease in relative humidity below 75 % due to changes in the operating modes of tunnel ventilation. The simulation results were confirmed by experimental tests in the subway and implemented for use.