An automatic fire searching and suppression system for large spaces

ARTICLE IN PRESS
T. Chen et al. / Fire Safety Journal 39 (2004) 297–307 305
3. Experiment
Experiments were conducted in a large test hall which is 30 m high, 30 m long and
18 m wide. The fire monitor was installed on one wall at the height of 6 m. Fuels in
different tests were placed in a line on the ground of the hall every 2 m from the fire
monitor (recorded as L). In each test, the fire monitor started its search from the
horizontal-left limit. Water pressure is 4 bar. Different fuels, such as diesel oil, wood,
and paper box are tested separately. Fig. 6 shows the experimental setup.
Usually, the spraying lasts for 10 s and during this time the chamber will swing in
75 in all directions for 3 times.
Table 2 shows the data for diesel oil fire tests. The fire is a 0.2 m 0.2 m pool fire
ignited by flock.
In all tests, the values of e are obtained by eyeballing and are of low precision.
Searching time T s varied in different tests, but usually it was less than 30 s if a fire is
found. In the test data of the same fire type, all the former three T s values were
obviously greater than the later three T s values. This was caused by the limitation of
the CCD camera’s vision field since the fire monitor started its search from the same
point in our tests. Fires farther than 16 m were detected in 1–2 scanning period
(reference to Fig. 3) and fires between 10 and 16 m were detected in 3–4 scanning
period (reference to Fig. 3) after the fire monitor chamber pivoted down. Generally,
Fig. 6. Experimental setup.
Table 2
Experimental data (diesel oil)
Number Fire type L (m) d=(h w 2 +L 2 ) 0.5 (m) d c (m) T s (s) e (m) T (s)
1 Diesel oil 10.0 11.66 11.86 25.3 0.3 5.1
2 Diesel oil 12.0 13.42 13.14 22.2 0.1 3.2
3 Diesel oil 14.0 15.23 15.07 23.8 0.2 4.0
4 Diesel oil 16.0 17.09 17.26 14.9 0.1 3.7
5 Diesel oil 18.0 18.97 18.93 12.2 0.0 2.9
6 Diesel oil 20.0 20.88 20.30 12.3 0.1 4.2