An analytical model to predict the temperature in subway-tunnels by coupling thermal mass and ventilation

Sun, T., Luo, Z. ORCID: https://orcid.org/0000-0002-2082-3958 and Chay, T. (2021) An analytical model to predict the temperature in subway-tunnels by coupling thermal mass and ventilation. Journal of Building Engineering, 44. 102564. ISSN 2352-7102 doi: 10.1016/j.jobe.2021.102564

Abstract/Summary

There is an increasing incidence of overheating in subway tunnels in recent years especially in old subways without air-conditioning e.g., London Underground. There is still lack of a clear understanding how tunnel-air temperature is determined by the complex thermal processes in subway tunnels. In this study, a mathematical model that describes the thermal processes in deeply buried subway tunnels was developed. Analytical solution was derived by separating the solution into time-averaged component and periodic component. The results show that the time-averaged component of tunnel-air temperature will approach steady state as the time tends to infinity, which has a positive linear relation with internal heat-source and average ambient temperature. Active cooling or heat-recovery systems could soon become a necessity in subway tunnels due to both global warming and increasing internal heat generation. Compared with outdoor air, the amplitude of the tunnel-air temperature shows a significant reduction in the day period but not in the year period. The surrounding soil temperature will keep changing for thousands of years. This study offers a new physical insight to analyse and mitigate overheating in subway tunnels.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/97472
Identification Number/DOI	10.1016/j.jobe.2021.102564
Refereed	No
Divisions	Science > School of the Built Environment > Urban Living group Science > School of the Built Environment > Energy and Environmental Engineering group
Publisher	Elsevier
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