Gas detection for tunnel February 1st 2009 Over 500 Crowcon detectors have been chosen by Telefonica Ingenieria de Seguridad for installation throughout the 28km long Guadarrama Tunnel in Spain.
Carbon monoxide (CO), nitrous dioxide (NO2) and oxygen (O2) levels are measured by
intrinsically safe Xgard detectors (validated to IEC61508 SIL2/3), while methane (CH4) levels are detected using Crowcon's flameproof (Exd) infra-red Nimbus units. Signals from all these detectors are processed by over 70 Vortex rackmounted controllers, which are connected to PLCs via RS485 and provide operators with all gas readings and alarm/fault information.
If any of the detectors register dangerous levels of any of the gases, ventilation and exhaust systems are automatically triggered by the Vortex control panels, which also pinpoint which detector is in alarm mode and immediately transmit this information via PLC to a SCADA system which transmits the information to control rooms in Madrid and Segovia.
Internal combustion engines emit exhaust fumes that contain significant quantities of CO and NO2. If a tunnel is inadequately ventilated, these gases can accumulate to concentrations that can become hazardous to human health. More articles from Crowcon Detection Instruments Ltd: |