Environmental Engineering Reference
In-Depth Information
The temperature range listed in the table is 291
5,000 K. Calculation detail is in the
-
following paragraph.
First, a explosion temperature is assumed. According to this explosion temper-
ature and data in Table
3.12
, all internal energy of explosion product
D
E is cal-
culated, and compared with the explosion heat Q
v
. If the deviation is very large,
then another temperature is assumed to recalculate
D
E is very close to
Q
v
, the assumed temperature can be considered as the explosion temperature.
With ammonium/TNT explosive mixture as an example, the explosion tem-
perature is calculated now. Explosive reaction equations of TNT/ammonium nitrate
explosive mixture is the following,
D
E. If this
11
:
35NH
4
NO
3
þ
C
7
H
5
NO
2
ð
Þ
3
!
7CO
2
þ
25
:
2H
2
O
þ
12
:
85N
2
þ
0
:
425O
2
þ
4748
:
84 kJ
Assuming its explosion temperature is 3,200 K, we can obtain according to
Table
3.12
:
D
E
CO
2
¼
142
:
25 kJ
=
mol
D
E
H
2
0
¼
111
:
52 kJ
=
mol
D
E
N
2
¼
76
:
22 kJ
=
mol
D
E
O
2
¼
82
:
14 kJ
=
mol
Thus, the total internal energy is:
D
E
¼
7
142
:
25
þ
111
:
52
25
:
2
þ
76
:
22
12
:
85
þ
82
:
14
0
:
425
¼
:
4862
23 kJ
=
mol
This number is larger than Q
v
= 4748.84, indicating the assumed temperature is a
little bit high. Therefore, the explosion temperature is reassumed as 3,000 K and the
following total internal energy can be obtained according to Table
3.12
:
D
E
¼
7
131
:
30
þ
25
:
2
102
:
37
þ
12
:
85
70
:
45
þ
0
:
425
57
:
78
¼
4436
:
30 kJ
=
mol
This result shows that the assumed temperature is too low. Thus, explosion
temperature of this explosive mixture is between 3,000 and 3,200 K. Assumed that
D
E value has a linear relationship with temperature within this temperature range,
we can obtain:
4862
:
23
4748
:
84
4862
:
23
4436
:
30
200
3200
T
¼
¼
3
;
163 K
