Post on 07-Dec-2020
09.09.2013/Rog ITS 2013 1
SIMPLE AND RELIABLE FIRE
DETECTION IN ROAD TUNNELS
Dr. Arnd Rogner
Metaphysics SA
Actual detection technologies (in Europe)
Field experience in tunnel fire detection
System integration
Contents
09.09.2013/Rog 2 ITS 2013
Road tunnel fire detection technologies (Europe)
09.09.2013/Rog 3 ITS 2013
Line type heat detectors (LTHD)
Measuring heat emission from fire
Visibility monitors / smoke detectors
Measuring smoke density
Video analysis
Reacting on different parameters like stopped vehicles, smoke
density, or open flames
Road tunnel fire detection technologies (Europe)
09.09.2013/Rog 4 ITS 2013
Line type heat detectors
(LTHD)
Absolute temperature
and/or rate-of-rise detection
Temperature profile
Loop installation with 2
control units for increased
availability
Semiconductor and fiber
optic systems
Road tunnel fire detection technologies (Europe)
09.09.2013/Rog 5 ITS 2013
Description:
Temperature sensor cable with
individual sensors in a distance of
4 m to 10 m for road tunnel application
Temperature measurement by
semiconductor sensors using the band
gap effect
Comments:
Threshold of each sensor editable
Reaction in RABT test 30 to 60 sec
No maintenance
LTHD Systems: Semiconductor sensor cable
09.09.2013/Rog ITS 2013 6
Description:
Fibre optic measurement system with
laser (OTDR or OFDR or code
correlation measurement)
Comments:
Different generations with different
specifications on the market
In certain solutions we have a
dependence: spatial resolution –
temperature resolution – length of the
system - detection speed
LTHD systems: Fibre optic sensor cable
09.09.2013/Rog ITS 2013 7
Visibility Measurement / Smoke Detection
Visibility monitors or special smoke
detectors
Description:
Optical scattered light or transmission
measurement
Installation distance 100 … 300 m
Comments:
Low fault alarm rate (scattered light)
Heating system to avoid interference
by fog
09.09.2013/Rog ITS 2013 8
CCTV Based Information System
Description: Pictures of CCTV cameras in
the tunnel are analyzed
Comments: Response speed: high
(smoke and fire)
Alternative: detect stopped vehicle
Non-negligible false alarm rate
Manual alarm verification required
Useful for early fire detection in tunnels with high risk potential
09.09.2013/Rog ITS 2013 9
LTHD specified in most countries for tunnel fire detection
E.g. DE, CH, AT, ES, CN, KR, TW, SP, BR, CO,…
Several countries request smoke detection in addition
E.g. DE, CH, SK
In addition smoke detection is used in more countries, even if it
is not yet required in a directive
Some countries just request fire detection,
but do not specify the technology
Can be LTHD, smoke, video-based detection
Some countries use no automatic fire
detection
Fire detection in road tunnels - guidelines
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Field experience
09.09.2013/Rog 11 ITS 2013
Fires by accident
Tauern 1999
Gotthard 2001
Gleinalm 2001
Viamala 2006
Fires by defects
Gotthard Ø 4 per year
- Overheating
- Turbocharger damage
- Tire fire
- Blocked brakes
We have different kinds of fire
09.09.2013/Rog 12 ITS 2013
Most fires start with smoke, before we get
open flames
Tauern and Gotthard fires would have
been detected earlier by smoke detection
Pool test fires in this sense are not
mirroring the reality
Smoke is faster than heat
09.09.2013/Rog 13 ITS 2013
Test # Fire size Wind
velocity
Detection time
smoke
detectors
Detection time
LTHD
1 0.1 MW 1.6 M/S 2:13 2:24
2 0.5 MW 1.6 M/S 1:29 1:07
3 1 MW 1.6 M/S 1:34 0:34
4 0.1 MW 1.15 M/S 1:25 1:23
5 0.5 MW 1.15 M/S 1:10 0:53
6 1 MW 1.15 M/S 0:57 0:25
7 CAR FIRE 1.55 M/S 0:52 2:53
8 3 MW POOL 1.8 M/S 1:23 0:25
Smoke is faster than heat
09.09.2013/Rog 14 ITS 2013
Results of Runehamar tests 2007
From: ARALT, T.T., NILSEN, A.R. (2009): Automatic Fire Detection in Road Traffic Tunnels;
Tunneling and Underground Space Technology, Vol. 24/1, pp.75-83
In case of a real car fire, smoke detectors can be
(significantly) faster than thermal detection
Pool fires give nice reproducible test conditions for
approval and test of system, but they are not mirroring
the reality of a car fire
In case of fires after accidents with fuel spills and
instantaneous developing open fires, the thermal
detection will be faster
Smoke is faster than heat
09.09.2013/Rog 15 ITS 2013
What happens, if a burning vehicle
continues to drive?
Truck drivers are even trained to
do so
How will our detection system
react?
Moving vehicles in fire
09.09.2013/Rog 16 ITS 2013
Moving vehicles in fire
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Location
Time
Turbocharger damage
in Gotthard tunnel
From: GRÄSSLIN, URS (2010):
Erfahrungsbericht Rauchdetektion
aus dem Gotthardstrassentunnel;
Proceedings of 9th Symposium
„Sicherheit im Strassentunnel
durch Einsatz moderner
Messtechnik“, Sigrist-Photometer
AG, Geroldswil
Localization by smoke is more difficult, as smoke is
spreading over a certain distance
More complex algorithms are required to control the
ventilation
CCTV cameras might be
blind due to high smoke
density
Temperature detection
is the only way to identify the
position of the burning
vehicle
Moving vehicles in fire
09.09.2013/Rog 18 ITS 2013
Temperature
Smoke
Important properties of thermal detection
09.09.2013/Rog 19 ITS 2013
Avoiding fatalities in tunnel fires is
mainly driven by self rescue
Simulations show that the number of
fatalities is proportional to the
detection time of the fire (or in fact to
the time informing the users and
their reaction)
If we reduce the detection time, we
also can reduce the number of
fatalities
Importance of fast detection
09.09.2013/Rog 20 ITS 2013
Tunnel Test 1 Test 2 Test 3 Test 4
Felderhalde 37 s
5 MW, 5m/s
- - -
Kohlberg Nord 31 s
5 MW, 6m/s
52 s
2.5 MW, 3m/s
ca. 60 s
5 MW, >6m/s
-
Kohlberg Süd 50 s
5 MW, 6m/s
52 s
2.5 MW, 3m/s
44 s
5 MW, 6 m/s
58 s
2.5 MW, 3m/s
Stauffer - 28 s
5 MW, 6m/s
52 s
2.5 MW, 4m/s
50 s
1.25 MW, 2m/s
Schwetzingen -
26 s
5 MW, 6m/s
- 26 s
5 MW, 6m/s
Ditschhardt 36 s
5 MW, 6m/s
70 s
2.5 MW, 2m/s
Fast detection – approval test fires in Germany
09.09.2013/Rog 21 ITS 2013
5 MW Brand according to RABT
Fast detection – test fire Ditschhardttunnel
09.09.2013/Rog 22 ITS 2013
After detection the smoke valves and/or
supression systems are triggered
The zone length typically is 100 m for smoke
valves and 25 m for supression systems
The adressing of the correct zones is crucial
for the lifes of the users
Influence of air speed
Detection of radiation heat
Influence of drift for FO systems
Needs regular recalibration
The precise localisation is important
09.09.2013/Rog 23 ITS 2013
Precise detection – test fire Ditschhardttunnel
Temperature profile MHD 535
09.09.2013/Rog 24 ITS 2013
Precise localisation of the fire
09.09.2013/Rog 25 ITS 2013
Absolute temperature threshold at 60°C
Backup
Gradient threshold at 3°C / 20 sec (9°C / minute)
Standard reaction type in real fires and tests
Dual-detector-dependence helps to reduce false alarms
- 1 sensor has to have 2 alarms in sequence
- 2 sensors give alarm at the same time
Under difficult conditions (e.g. sunlight at entrance), the gradient
condition can be increased up to 5°C / 20 sec
Alarm criteria for thermal detection
09.09.2013/Rog 26 ITS 2013
Systemintegration
09.09.2013/Rog 27 ITS 2013
System integration fire detection: Example D / A
09.09.2013/Rog 28 ITS 2013
Tunnel monitoring and control system
Alarm activities:
- Ventilation
- Escape Lights
- Fire Brigade
- Closure
- …..
FAP
PU
FAP
PU
GW
LTHD
Relays
Building Fire Detection
Manual Callpoints Tunnel
Fire extinguisher contacts
etc.
Redundance
Ala
rms
Ala
rms
Tem
pera
ture
-
valu
es
Sm
oke d
ete
ction
System integration fire detection: Example CH
09.09.2013/Rog 29 ITS 2013
Tunnel monitoring and control system
Alarm activities:
- Ventilation
- Escape Lights
- Fire Brigade
- Closure
- …..
FA
P
Build
ing,
etc
.
PU PU
GW
LTHD
Ala
rms,
Tem
pera
ture
-
valu
es
GW
Redundance
Sm
oke d
ete
ction
Challenge
Different system architecture in different countries (projects)
Partly using different interfaces / protocols
(Modbus TCP/IP, Profibus, IEC 60870-5-104, …)
This requires different integration concepts and components
The cost for the integration part is increasing
Redundancy for all signal / information transmission
Standardization would make sense
System integration fire detection
09.09.2013/Rog 30 ITS 2013
Thermal detection is mandatory. It is the most reliable method and
the only one to localize a fire in case of a smoke-loaded tunnel
The thermal detection can localize a fire within 10 m (or even less)
For the selection of a linear heat detector, reaction time, precision of
localization, and maintenance effort should be regarded
Smoke detection is a recommended addendum, as small car fires
are seen significantly faster. Users can win several minutes to
escape
A standardized integration concept could reduce cost
Conclusion
09.09.2013/Rog 31 ITS 2013