PERFORMANCE CHARACTERIZATION OF A MULTI-STAGE SOLAR STILL - Energy Research Developments: Tidal Energy, Energy Efficiency and Solar Energy - page 142

This method has allowed us to evaluate the distillate flow rate produced by a three-cell
distiller. This flow rate increases with the heat flux density (figure-7). In practice, the solar
heat flux density does not go beyond 1000 W/m 2 , which corresponds to a production of 1.5
kg/m².h, thus to a total daily production limited to 12 kg/m² if it is supposed that in summer,
the apparatus works during eight hours in mean. This distillate flow rate is larger than that of
a classical one-stage distiller which is around de 4 kg/m² per day in similar conditions.
Note that the results thus obtained for a three-stage distiller are in agreement with those
of Bouchekima [27].

1.2

1

0.8

0.6

0.4

20 25 30 35 40 45 50

T feed (°C)

Figure 8. Distillate flow rate for a three-stage distiller: Influence of the feed temperature.

The production of the distiller increases with the temperature of the feed water (figure 8),
from 0.6 to 1.1 kg/m 2 .h when the feed temperature increases from de 25 to 45°C .

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

0 5 10 15 20 25

m feed (kg/m².h)

Figure 9. Distillate flow rate of a three-stage distiller: Influence of the feed flow rate.