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IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask C2-A, November 9, 2009
of the bundle dripping into the sump, and at the exit of the sump. Figure 2 shows the
concentration and mass flow definitions, introducing time-discrete parameters (index i).
Figure 2. Definition of concentrations and mass flows in generator/absorber. Solid lines: strong solution,
dotted lines: weak solution, white arrows: vapour.
Solution transport delay
A transport delay (c) is assumed to occur in both solution circuit legs. Referring to Figure 2,
the inlet values of solution mass flow
& * and concentration
m
sol,
sA,
i
∗
x
sA , i
at the absorber at time
interval i are assumed to equal the generator outlet values of time interval (i-c 1 ). The
superscript * symbolizes the time-delayed arrival of the solution at absorber and generator
inlet. By analogy, the inlet value of concentration
x
∗
wG i
,
at the generator at time interval i is
assumed to equal the outlet value of the absorber at time step (i-c 2 ). Constants c 1 and c 2
account for the time which the solution needs to flow from generator to absorber and vice
versa. They are integers representing a number of simulation steps.
Absorber:
x
= x
(11)
∗
sA, i sA,
i−c1
m& = &
(12)
*
sol,
sA,
i
msol,
sG,
i−c1
Generator:
x
= x
(13)
∗
wG , i wG , i−c2
m& *
, ,
m&
, , 2
const.
(14)
sol wG i
=
sol wA i−c
=
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