Upgrade of a transverse ventilation system in a bi-directional tunnel

Abstract

The Karavanke tunnel forms an important link between Slovenia and Austria. The almost 8 km long tunnel is operated with bi-directional traffic and does not have dedicated escape routes. Moreover, the ventilation in case of fire does not satisfy requirements of the EU Directive 2004/54/EC that specifies the minimum requirements for tunnels in the trans-European road network. The paper present results of the research conducted regarding the possibility of upgrade the existing system in order to reach the required level of safety at lower costs possible. It is shown that with simple but novel adaptations of the ventilation system, a sizeable increase in the overall level of safety can be achieved. The methodology applied is a combination of a simple pipe model for tunnel ventilation and for detailed fluid dynamics analysis the CFD model is used. The existing ventilation system that in fire ventilation extracts smoke from a single duct is replaced with the smoke extraction from both ducts applying four axial fans. The analysis is focused on air/smoke flow through the vents and ducts and on pressure drops calculated over the length of the ventilation duct and its influence on the total flow. The change of the flow condition also has influence on ventilation fan operation point that is investigated in the paper as well

Experimental study on heat exhaust coefficient of transversal smoke extraction system in tunnel under fire

“…c o m / l o c a t e / t u s t 2010; Fan et al, 2013;Li and Chow, 2003;Lin and Chuah, 2008;Lu et al, 2013;Ni et al, 2010;Porizek et al, 2007;Rie et al, 2005;Vauquelin and Megret, 2002;Vidmar et al, 2012). Experimental study (Choi et al, 2005;Ni et al, 2010;Porizek et al, 2007;Vauquelin and Megret, 2002) and numerical simulation (Ballesteros-Tajadura et al, 2006;Colella et al, 2010;Li and Chow, 2003;Lin and Chuah, 2008;Lu et al, 2013;Rie et al, 2005;Vidmar et al, 2012) with both isothermal and thermal models were carried out to study the performance of different transversal smoke extraction systems of tunnels. Vauquelin and Megret (2002) conducted experiments in a 1:20th tunnel to investigate the influence of fire source and outlets on the exhaust coefficient.…”

Influence of Fan and Duct Layout Parameters on the Effectiveness of Tunnel Ventilation and Dust Removal

“…Zhou Yang [22] et al established a gas transport model in the tunnel through numerical simulation of computational fluid dynamics, and investigated in detail the effects of four duct layout parameters, namely, different duct diameters, distance of the duct opening from the working face, the duct suspension position and the gap between the ducts and the wall, on the tunnel wind flow field and gas distribution law. Vidmar [23] used CFD software to reasonably optimize the existing ventilation system, and reconfigured the ducts and fans to effectively reduce the investment cost. , effectively reducing the investment cost.…”

Temperature stratification in a road tunnel

“…It is necessary to have a ventilation strategy to control a smoke flow. Same for tunnels that have a ventilation strategy, we conducted research to improve the efficiency of the ventilation system in order to increase the level of security such as the study of Vidmar et al [1].…”