Environmental Engineering Reference
In-Depth Information
X
Q
pm
¼
26
:
05 4a
þ
b
p
ð
Þ þ
f
j
D
j
ð
3
:
17
Þ
where,
a, b
the molar numbers of carbon atom and hydrogen atom in 1 mol (or 1 kg) of
the material,
p
number of electrons of carbon and hydrogen atoms connected to oxygen
atoms, i.e., the number of C
O and H
O bonds;
-
-
f
j
j-type substituents in the molecule including the number of short covalent
bond,
thermochemical corrected value of j-type substituent.
D
j
This equation is good to calculate, relatively accurately, the combustion heat of
liquid explosives. While, in the calculation of combustion heat of solid explosives,
the right part of equation must be deducted off its fusion heat. If the substance is
gas, the vaporization heat should be added. In this method, the standard temperature
used is T
b
= 298.15 K.
Therefore, the formation heat can be calculated according to the substance
formula and combustion heat of
final products after the complete combustion. The
calculation method is still explained with the triangular diagram, which is similar to
that to obtain explosion heat (Fig.
3.4
).
In Fig.
3.4
, State 1 corresponds to a stable state of a simple element, State 2
corresponds to the explosive, and State 3 corresponds to the combustion products of
explosive, thus, the following can be obtained.
Q
0
1
;
2
þ
Q
0
2
;
3
¼
Q
0
1
;
3
And the formation heat of explosive Q
0
1
;
2
can be obtained from the following
equation:
Q
0
1
;
2
þ
Q
0
1
;
3
¼
Q
0
2
;
3
Fig. 3.4 The triangle
diagram to calculate
combustion heat
Explosives
Q
1,2
Q
2
,3
Stable substance of
element
Combustion
products
