High Bay Fire Detection Tests.
High Bay Fire Detection Tests.
(1643 K)
Davis, W. D.
Fire Suppression and Detection Research Application
Symposium. Research and Practice: Bridging the Gap.
Proceedings. Fire Protection Research Foundation.
February 24-26, 1999, Orlando, FL, 265-291 pp, 1999.
Keywords:
fire suppression; fire detection; fire research; fire
safety; fire protection; aircraft hangars; ceiling
height; smoke detectors; heat detectors; JP-5 jet fuel;
JP-8 jet fuel; pool fires; draft curtains; sprinkler
response; windows; fire models; wind effects
Abstract:
A series of fire experiments were conducted in two
aircraft hangars with ceiling heights of 15 m (50 ft)
and 22 m (73 ft). The purpose of the experiments was to
analyze the activation characteristics of smoke and heat
detectors in response to JP-5 and JP-8 pool fires. The
15 m (50 ft) hangar was located at Barbers Point, Hawaii
where ambient temperatures were approximately 30 deg C
(86 deg F). The 15 m (50 ft) experiments used fire sizes
which ranged from 100 kW (95 Btu/s) to 7.7 MW (7300
Btu/s). Experiments were conducted with and without
draft curtains in the 15 m (50 ft) hangar. The 22 m (73
ft) hangar was located at Keflavik, Iceland where
ambient temperatures were approximately 12 deg C (54
deg F). The 22 m (73 ft) experiments used fire sizes
which ranged from 100 kW (95 Btu/s) to 33 MW (31000
Btu/s). Draft curtains were present for all the 22 m (73
ft) experiments. Open and closed door fire experiments
were conducted at both hangars. Commercial detectors
used in the series of experiments included spot smoke
and heat detectors, bulb and fusible link elements,
projected beam smoke detectors, UV/IR optical flame
detectors, and a line-type heat detector. Other
instrumentation included thermocouples, mass flow
meters, and radiometers. The analysis of these
experiments has led to the following observations. 1.
Draft curtains improved the response time of heat
detectors and sprinklers at these heights and reduced
the size of the threshold fire needed for activation.
Both the plume centerline temperature and the ceiling
jet temperature increased in response to the growing
layer. 2. Standard response sprinklers either
activated substantially slower or not at all when
compared to the activation of quick response sprinklers
at these heights. 3. Trouble windows used for beam type
smoke detectors gave false trouble signals in the
presence of dense smoke from JP-5 fires. 2. Tests
conducted in the presence of wind and open hangar doors
showed that ceiling jet temperatures were substantially
reduced but that downwind smoke detectors continued to
activate for small fire sizes. Wind speeds inside the
hangar ranged from 2 km/h to 32 km/h (1 mph to 20 mph).
Based on the observed detector activation, spacing for
both spot smoke and heat detectors at these height was
analyzed.
