Abstract
Aim: The purpose of this paper is to reveal the outcome from studies performed by the authors about smoke and heat ventilation systems for underground railway buildings using an underground railway network as an example. Research activity examined, in particular, the link between air supply methods to an underground station area with the effective performance of a longitudinal ventilation system at such a station. The intention for this publication is to increase the design credibility for longitudinal ventilation solutions, including solutions for underground stations, by highlighting associated advantages and disadvantages. This article is based on experimental study results, which were presented at an international conference “Underground Buildings and Road Safety, and the Urban Infrastructure” (Budownictwo podziemne i bezpieczeństwo w komunikacji drogowej i infrastrukturze miejskiej), Kraków 2016.
Introduction: Longitudinal ventilation systems provide one of the approved solutions for underground railway stations and are based on similar solutions applied in the ventilation of road tunnels. Such system may provide similar environmental conditions as with transverse systems, at the same time preserve areas throughout the station from smoke and ensure safe access for firefighting and rescue teams. In order to achieve this, a key issue, which must be addressed, concerns the choice of supply strategy for the delivery of air to the underground location. This may be by mechanical as well as natural means. Likewise, the volume relationship between air supplied by mechanical and gravitational means has a crucial impact on the performance of the ventilation system. The authors reveal results from a short programme of numerical studies, which analysed the air flow relationship to achieve an optimum balance, and the consequential performance of fire ventilation systems on station platforms.
Methodology: The study reveals results from original research performed by the authors, which is based on the literature review in this area, using the Computational Fluid Dynamics method (CFD), Additionally, numerical study results are supported by the authors personal experience acquired through numerous hot smoke tests performed during the commissioning phase of the Warsaw Metro, Line 2.
Conclusions: Longitudinal systems can provide similar environmental conditions as traditional transverse systems. During firefighting and rescue operations, longitudinal systems provide more safety for firefighters than transverse solutions. The key role in the system performance can be attributed to the supply method and volume of air provided by mechanical means.
Keywords: fire ventilation, tunnel ventilation, longitudinal ventilation, underground railway, air supply
Type of article: case study