Separation and Evaluation of Simultaneous Heat-Mass Exchange in Subway Tunnels

Abstract

During simultaneous heat and mass transfer between a ventilation flow and a surrounding massif, the heat flow is supported by the mining massif, and the moisture flow is due to hygroscopic processes occurring only within the tunnel's concrete support. This is result of using moisture resistant membranes between the mining massif and the underground space. The simultaneous heat and mass transfer processes in the presented paper considered on the basis of -theorem and established a new criterion by means of it is possible to divide processes heat and mass transfer at the two-component system "massif-air". The new criterion relates a thermal resistance 1/  with mass transmission analogical resistance 1/  m within the limits of corresponding boundary layers. Thus, estimation of a ventilation air flow by it appears to be possible as both of those values are the current characteristics. As a result, it may be concluded that separation and evaluation of simultaneous heat mass exchange processes using the criterion introduced in this paper is possible..