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Related Quantities. Part A. Heat of Combustion and Potential Heat.

Related Quantities. Part A. Heat of Combustion and
Potential Heat.
(798 K)

Babrauskas, V.

Chapter 8;

Heat Release in Fires, Elsevier Applied Science, NY,
Babrauskas, V.; Grayson, S. J., Editor(s)(s), 207-223
pp, 1992.

### Keywords:

heat release rate; fire protection engineering; heat of
combustion; potential heat

### Abstract:

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In a combustion reaction, the essential quantity is the
heat of reaction. Since in typical combustion reactions
we are dealing with constant-pressure, rather than
constant-volume systems, it is most convenient to work
with enthalpies, rather than energies. The enthalpy, H
(kJ), is defined as: H = U + PV where U is the energy
(kJ), P is the pressure (kPa), and V is the volume (m3).
In thermodynamics and engineering calculations, specific
enthalpy, h, is often used (and also specific energy,
u). Molar units (kJ/mol) for these terms are typical in
thermodynamics calculations, while in engineering
computations it is often convenient to adopt mass
(kJ/kg) units.
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