In this webinar the focus lies on two sensors which are very important in case of tunnel fires:
- Optical smoke detectors which meanwhile are state-of-the-art for early and reliable fire detection in many countries, and
- Cross-tunnel ultrasound air flow measurements for controlling the smoke extraction
Optical smoke detectors can be either air aspirating or diffusion based. For the diffusion based types, the design is crucial for ensuring short response times and the detection itself, particularly in case of slow air speed. The major design criteria for ensuring this performance will be presented.
The air speed measurement must be in operation as long as possible during a tunnel fire. Therefore, the ultrasound has to pass through dense smoke clouds. The webinar shows, how this is achieved and was tested in a real tunnel fire test.
- Aspects of tunnel ventilation in standard operation versus fire scenarios
- Optical smoke detectors at low air speeds
- Performance of ultrasonic cross tunnel measurement during tunnel fires