
552 Fuel Cells
cathode based on inlet molar ow rate. These terms do not account for
changes owing to reactions and therefore the second and fourth terms
correspond to the heat produced or lost by reaction in both the anode
and cathode. It is assumed that the anode and cathode exhaust exit at the
stack temperature.
The ideal gas assumption allows the partial molar enthalpies to be writ-
ten as a function of specic heats at a constant pressure. The partial molar
enthalpies are computed using
hh cu
ii i
T
T
=+
∫
ref
p,
d
ref
()
, (12.62)
where the specic heats are calculated using
c
p,i
= a
i
+ b
i
T + c
i
T
2
+ d
i
T
3
. (12.63)
The coefcients of specic hea