Control of thermodynamic parameters of the air environment of subway lines with single-track deep tunnels

Introduction. The purpose of this study is to study the patterns of thermodynamic parameters of the air environment for subway lines with single-track deep tunnels. This is important when controlling the thermodynamic state of the air environment at stations and distillation tunnels using the patterns of aerothermodynamic processes. Materials and methods. The work carries out a full-scale experiment to assess the thermodynamic parameters (temperature and humidity) of underground structures during periods of movement and absence of trains, the research was carried out with iButton Temperature Loggers thermographs. Results and discussion. Graphs of the distribution of air temperature, lining surface and humidity in tunnels on the stages "Primorskaya"–"Vasileostrovskaya" – Gostiny Dvor" during movement and absence of train movement are constructed. The change in air temperature along the length of the runs is variable, with revealed maximum values at stations and minimum values in the central parts of the runs, which is fully correlated with studies conducted earlier. This is due to different ventilation schemes during the day and night periods. At the same time, the air temperature has lower values than the surface temperature of the lining, due to the warming of the ground during the daytime when trains are moving. Conclusion. The peculiarities of the formation of ventilation and thermal regimes of the considered subways made it possible to formulate the principles of ensuring the normative climatic parameters of the air environment. Suggestions for practical applications and directions for future research. The developed methodological approaches can be useful in planning design solutions for the ventilation of deep–laid metro stations, as well as can be applied to evaluate existing Russian subways and improve the thermal and ventilation modes of the subway line.