Ventilation Belliard-tunnel Brussel, Belgium PROJECT IN ... - Traficon

PROJECT IN THE SPOTLIGHT:Ventilation Belliard-tunnelBrussel, BelgiumThe Belliard-tunnel is an urban tunnel in the centre ofBrussel.It is a complex tunnel, not only because of its length and itsseveral access and exit roads, but also because of its Y-shape. This shape is due to the assembling of parts of threepreviously existing tunnels. The length between the entranceat Belliard Street and the east portal is 2100m. With a threelaneentrance, it forms a four-lane tunnel in its first part to splitinto two separate two-lane roads after 460m.The real-time traffic data gathered by the video detectionsystem are fed into the tunnel ventilation control system tooptimise the ventilation in case of incidents or duringcongestion.The advantage of using traffic datainstead of pollution data for ventilationcontrol is not only a gain in terms ofenergy saving, but also in terms of ashorter response time of the system.Started in 1992, the installation was completely operational inDecember 1994.Each of 11 cameras, monitoring two lanes, is connected to aCCATS video image processor (predecessor of the VIP/D).The following data are provided as input for the tunnelventilation: mean speed (km/h) traffic volume (vehicles/min) linear density (vehicles/km)These data are collected by a computer and then transferredto the Landis & Gyr Central Tunnel Management Computer.The advantage of using traffic data instead of pollution data isnot only a gain in terms of energy saving, but also in terms ofa shorter response time of the system.

Axial fans (26) are set up in groups of two fans operating in parallel.Additional jet-fans (44) are installed to ensure a sufficient ventilationcapacity at any one of the tunnel sections.The objective of the ventilation control system is mainly two-fold: first, it must provide ventilation systems that are economical inroutine operation while diluting pollutants sufficiently secondly, it must control the ventilation as safely and efficiently aspossible in emergency cases resulting from breakdowns, accidentsor fire.SYSTEM AT A GLANCE11 CCATSCCATS : Camera andComputer Aided Traffic Sensor,for collection of standard trafficdata such as mean speed,volume and linear densitycurrent VIP/D replaces CCATSUsing traffic data as control variables (number of vehicles per km, average traffic speed and unbalance betweenboth the exit sections for concentration and for speed) allows one to prepare in advance, by means of numericalsimulations, a certain number of ventilation configurations. Each configuration is defined in a table containing theset points of all fans.Observation in the Belliard-tunnel shows that the action on the ventilation would not have been so fast if themeasurements of CO or NO 2 concentration were used instead of the traffic information.FOR MORE INFORMATION, PLEASE CONTACT MR. KOEN SOENENS – TRAFICON (KS@TRAFICON.COM).THE BELLIARD-TUNNEL PROJECT IS A JOINT REALISATION OF THE MINISTRY, EGC, UCL/MITEC, PHILIPS, LANDIS & GYR,TRACTEBEL AND TRAFICON.Traficon, Vlamingstraat 19, B-8560 Wevelgem, Belgiumtel +32 (0)56 37.22.00 – fax +32 (0)56 37.21.96 - traficon@traficon.com - www.traficon.com Issue 2001