WIT Press


The Calculation Of Diurnal Temperature Variation In An Underground Railway System With Moisture Addition

Price

Free (open access)

Paper DOI

10.2495/HT960611

Volume

12

Pages

7

Published

1996

Size

590 kb

Author(s)

H. Barrow & C.W. Pope

Abstract

A finite-difference numerical analysis to determine the transient temperature in an intensively operated metro under irregular cyclic conditions has been extended to include the mass transfer of moisture in the ventilation air. The moisture addition takes place by evaporation from internal wetted surfaces. The histories of the dry-bulb temperature, the humidity of the tunnel air and the wall heat flux are obtained conjugately using a time-marching formulation of the energy and mass transfer equations. By comparing the prediction of the temperature variation with that for dry air, it is shown conclusively that increase in the humidity of the ventilation air significantly reduces the temperature rise in the tunnel due to the heat release. Provision is also made in the calculation for

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