integration of solid oxide fuel cells and ... - Ea Energianalyse

3. COMPONENT DESCRIPTION
T [° C ]
T h , i
T h , o
ΔT min ,r ,o
T ss , o
T r ,o
T ws ,i
˙Q[kW ]
Figure 3.8: Desorber: The solution/gas temperature is assumed to be constant throughout the
desorber. So the closest approach temperature difference will be between the heating water outlet
and the common solution temperature.
heat capacity flow:
ɛ = T h,i − T h,o
T h,i − T ss,o
(3.30)
The amount of heat to be added by the heating circuit is calculated by
the energy balance, which includes a loss to the surroundings ( ˙Q loss ),
which should be zero (adiabatic component) or positive (heat loss to the
surroundings).
Ḣ ws,i + Ḣ h,i = Ḣ r,o + Ḣ ss,o + Ḣ h,o + ˙Q loss (3.31)
A mass balance is made for H 2 O as well as LiBr (total inlet = total outlet):
ṁ r,o + ṁ ss,o = ṁ ws,i (3.32)
ṁ ss,o · w ss,o = ṁ ws,i · w ws,i (3.33)
were w is the concentration of LiBr in the solution. The pressure losses
(given as a negative pressure increases) are defined as three different ∆P
parameters:
p r,o = p ws,i + ∆p r (3.34)
p ss,o = p ws,i + ∆p ss (3.35)
p h,o = p h,i + ∆p h (3.36)
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