IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask C2-A, November 9, 2009
Experimental validation of components’ model
The sensible regenerator
The outlet temperature of the sensible regenerator depends on the temperature at both inlets
of the regenerator. Various temperature differences between the inlets of the regenerator
(position 2 and 6) were considered. Figure 7 below plots the experimental efficiency of the
regenerator as well as the outlet temperature deviation of the model relative to the
measurements.
1
0.9
Efficiency
Deviation
Sensible Regenerator
1
0.9
0.8
0.8
Experimental efficiency [-]
0.7
0.6
0.5
0.4
0.3
0.7
0.6
0.5
0.4
0.3
Temperature deviation [ C]
0.2
0.2
0.1
0
0.1
5 10 15 20 25 0
Temperature difference (T 2 -T 6 ) [ C]
Figure 7: experimental efficiency of the sensible regenerator and deviation of the model
prediction of the outlet temperature with respect to measurements
Figure 7 shows that the measured efficiency of the sensible regenerator is nearly constant
and equal to 0.7 in all cases; it also shows that the error in predicting the outlet temperature
(position 3 in Figure 1) of the regenerator using the model presented above is low, never
exceeding 0.5°C. It should be noted that this devia tion is in the domain of the accuracy of the
measurements. This accuracy can be predicted, as the efficiency is constant, independent of
the operating temperature.
The desiccant wheel
For the desiccant wheel model, different inlet conditions (position 1 with reference to Figure
1) were considered with the temperature varying from 25°C to 38°C and the humidity ratio
from 10 to 15g/kg, and for different regeneration temperatures (60°C, 65°C, 70°C and 80°C).
Figure 8 plots temperature error against humidity ratio error for the most significant points.
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