258
7 The Role of Ventilation in Fires and Explosions
(c) The higher the velocity of the gases, the more difficult it will be for them to
exchange their heat with the gallery walls. This causes the gases to remain hot
while transported over longer distances.
(d) The table and plot show the values, obtained from Eq. 7.9, of T (°C) for
different distances (x) to the fire, depending on the air speed (v).
Speed (m s −1 )
2
4
6
8
10
Distance to the fire (x) (m)
0.5
798
798
799
799
799
1
795
797
798
798
798
10
756
772
778
782
784
30
679
719
737
747
754
50
612
672
698
714
725
80
528
608
646
668
684
100
480
570
613
640
659
150
387
489
542
577
601
250
268
371
432
474
505
500
142
216
270
312
345
750
95
147
189
223
253
1000
71
111
143
171
196
1500
47
74
96
115
133
2000
36
55
72
86
100
If, on the contrary, Eq. 7.6 were to be used, the following table would emerge.
Considerable differences relative to Eq. 7.9 may be observed, particularly for longer