HES-SO - ECOLE D'INGENIEURS DU CANTON DE VAUD –- LESBAT A NEW SOLAR POWERED ADSORPTION REFRIGERATOR WITH HIGH PERFORMANCE
4.5 Ventilation damper management Closing : when the irradiance goes above 100 W/m2. Opening : at the end of afternoon when the angle for the solar beam radiation incident upon the aperture plane of collector (angle of incidence) is above 50°.
5. METEOROLOGICAL CONDITIONS
Daily irradiation
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Mean external temperature
1st Period
2nd Period
30 25 20 15 10 5
28.09.01
23.09.01
18.09.01
13.09.01
08.09.01
03.09.01
29.08.01
24.08.01
19.08.01
14.08.01
09.08.01
04.08.01
30.07.01
0
25.07.01
Temperature [°C] ; Irradiation [MJ/m2]
The series of measurements took place from July 25th to September 30th 2001 (68 days) in Yverdonles-Bains (altitude : 433 m, longitude : –6.38°, latitude : 46.47°). The figure 3 shows the observed weather conditions (daily irradiation and mean external temperature).
Date Figure 3 : Evolution of the daily irradiation and mean external temperature during series of measurements (from 25th July to 30th September 2001). 1st period : Summer meteorological conditions with high mean external temperature and irradiation. 2nd period : Autumnal meteorological conditions with reduced mean external temperature and irradiation.
This graph shows two different periods : 1) From July 25th to the beginning of September : during this summer period, the mean external temperature is above 20°C and the mean daily irradiation reaches 22 MJ/m2. This fine weather period is interrupted between the 3rd and 9th August by less favourable weather. 2) From the beginning of September to the end of the measurement : the mean external temperature and the daily irradiation are distinctly lower (13°C and 13 MJ/m2). Furthermore, the conditions are very variable from one day to the next.
6. PERFORMANCE OF THE TESTED UNIT For each day, a gross solar COPSR can be defined as the ratio of the heat extracted by evaporation of water to the solar heat supply, see equation 1. The first one, Qe, is obtained by multiplying the mass of processed water, mL, by the enthalpy difference between the saturated vapour at Te and the saturated liquid at Tc. The second one, Qh, is the product of the surface A of collector and the solar
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