IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask C2-A, November 9, 2009
Figure 3 shows the partition of the generator vessel into the external (right side) and internal
(left side) part, Figure 4 shows the same partition for the absorber.
Figure 3. Enthalpy balance for generator vessel. Grey arrows: heat flow, white arrow: vapour flow, black
arrows: fluid flow. Left side: internal, right side: external
Figure 4. Enthalpy balance for absorber vessel. Grey arrows: heat flow, white arrow: vapour flow, black
arrows: fluid flow. Left side: internal, right side: external
Externally, all four chiller vessels incorporate water headers for the distribution of hot, chilled
and cooling water through the tube bundles. It is assumed that the headers and the water
mass enclosed in those contribute completely to the external heat storage. The tube bundles
are assumed to contribute by 50% of their mass to the external heat storage and by 50% to
the internal heat storage. This is reasonable because the falling film heat exchanger tubes
have flow on both sides, internally by LiBr/water solution and externally by water. The vessel
wall is assumed to contribute by 10% of its total weight to the external thermal mass due to
the conduction heat transfer from the headers.
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