IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask C2-A, November 9, 2009
Day 1:
1000
900
800
Solar global radiation -Day 1-
90
80
Outlet temperature -Day 1-
Experimental
Model
Radiation [W.m -2 ]
700
600
500
400
300
Temperature [ C]
70
60
50
200
100
40
0
0 100 200 300 400 500
Time [min]
30
0 100 200 300 400 500
Time [min]
Figure 10: comparison of the predicted outlet temperature of the collectors with the measured
one for perfect radiation conditions and a storage load
Comparison between the computed and the measured temperatures for the typical summer
day conditions shows the model’s high performance in predicting collector outlet temperature
with a negligible error. This accuracy is due to the fact that each component is taken into
consideration by the model and the calculations are performed in each vacuum tube
simultaneously (400 tubes).
While collector outlet temperature can thus be predicted accurately in normal radiation
conditions, it is very important to study the performance of the model for atypical conditions.
Day 2:
1200
1100
1000
Solar global radiation -Day 2-
100
Outlet temperature -Day 2-
Experimental
Model
900
90
Radiation [W.m -2 ]
800
700
600
500
400
Temperature[ C]
80
300
70
200
100
0
0 100 200 300 400 500
Time[min]
60
0 100 200 300 400 500
Time [min]
Figure 11: comparison of the predicted outlet temperature of the collectors with the measured
one for fluctuating radiation conditions and a storage load
page 39