Radiation-cooled Dew Water Condensers studied by CFD - Arcofluid
Radiation-cooled Dew Water Condensers studied by CFD - Arcofluid
Radiation-cooled Dew Water Condensers studied by CFD - Arcofluid
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<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
(<strong>CFD</strong>)<br />
Owen CLUS
2006 European PHOENICS User meeting<br />
Wimbledon, 30th Nov. 1st Dec., 2006<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong><br />
<strong>Condensers</strong> Studied <strong>by</strong><br />
Computational Fluid Dynamic (<strong>CFD</strong>)<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Owen CLUS Université de Corse<br />
Studied Jalil OUAZZANI <strong>by</strong> Computational <strong>Arcofluid</strong> Fluid Dynamic<br />
Université (<strong>CFD</strong>) de Corse<br />
Marc MUSELLI<br />
Vadim NIKOLAYEV<br />
Girja SHARAN<br />
Daniel BEYSENS<br />
CEA/CNRS-ESPCI Paris<br />
Indian Inst. of Management, Ahmedabad<br />
CEA/CNRS-ESPCI Paris<br />
International Organization For <strong>Dew</strong> Utilization
Atmospheric vapour harvesting <strong>by</strong><br />
radiative cooling<br />
Researches for condensing atmospheric<br />
vapor as alternative water resource in arid<br />
<strong>Radiation</strong>-<strong>cooled</strong> areas without energy <strong>Dew</strong> <strong>Water</strong> supplying <strong>Condensers</strong><br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
(<strong>CFD</strong>)
Atmospheric vapour harvesting <strong>by</strong><br />
radiative cooling<br />
Radiative budget - 70 W/m²<br />
Researches for condensing atmospheric<br />
<br />
vapor as alternative water resource without<br />
Surface 3 to 8°C below T ambient<br />
<strong>Radiation</strong>-<strong>cooled</strong> CLEAR energy SKY supplying<br />
<strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Insulation<br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
(<strong>CFD</strong>)<br />
substrate<br />
Innovative formulations<br />
<br />
cheap polymers<br />
LDPE, paint<br />
high IR emissivity<br />
polymer<br />
basis<br />
ROOF<br />
GROUND<br />
Radiative<br />
Filler
Pilots, Prototypes<br />
FRANCE<br />
FRANCE<br />
Experimental<br />
prototypes<br />
<strong>Radiation</strong>-<strong>cooled</strong> 1 m²<br />
<strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
1 m² 0.6 L / night<br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
<strong>Dew</strong> = 30 % INDIA of (<strong>CFD</strong>) rain<br />
15 m² 7 L / night<br />
30 m² 10 L / night<br />
Quantitative<br />
systems<br />
CROATIA<br />
800 m² 300 L/ night
<strong>CFD</strong> simulations of radiative condensers<br />
The <strong>CFD</strong> tool has been developed for helping<br />
decision and technical choices before<br />
implementing these huge systems without<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
preliminary empirical tests<br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
(<strong>CFD</strong>)
Radiative condenser as thermal machine<br />
Wind flow<br />
Radiative<br />
cooling<br />
Condenser<br />
shape and<br />
thermal<br />
condensation in<br />
weak wind, limit free /<br />
forced convection<br />
<strong>Radiation</strong>-<strong>cooled</strong><br />
properties<br />
<strong>Dew</strong> <strong>Water</strong> variability <strong>Condensers</strong> of<br />
Studied <strong>by</strong> Computational meteorological Fluid Dynamic data<br />
Free<br />
convection (<strong>CFD</strong>)<br />
heating<br />
induces long time<br />
outdoor experiments<br />
α<br />
r<br />
forced<br />
convection<br />
heating<br />
R<br />
no description for<br />
complex shapes<br />
without empirical<br />
corrections
Radiative cooling inclusion in <strong>CFD</strong><br />
Specific radiative cooling for each shape<br />
angular sky emissivity<br />
dR = (ε s,θ σT<br />
4<br />
amb – ε r σT rad4 ) dΩ<br />
<br />
1<br />
<br />
b cos<br />
, 1<br />
1 <br />
s<br />
s<br />
isotropic radiator emissivity<br />
ε r = 0.94<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
SKY<br />
(<strong>CFD</strong>)<br />
ε m<br />
0.94 dΩ<br />
ε s,θ<br />
θ<br />
α<br />
1
Radiative budget (W/m²)<br />
Radiative cooling inclusion in <strong>CFD</strong><br />
FORTRAN tool for integrating radiative budget on various shapes<br />
angular integration<br />
dissipation law included in Phoenics computation: E R = f(T)<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> 0 <strong>Water</strong> <strong>Condensers</strong><br />
plan 0.0°<br />
-10<br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
plan 30°<br />
-20<br />
cone 20°<br />
cone 30°<br />
(<strong>CFD</strong>)<br />
Puissance dissipée (W/m²)<br />
-30<br />
-40<br />
-50<br />
-60<br />
BILANS RADIADIFS (en ciel nocturne clair à 15°C)<br />
cone 40°<br />
-70<br />
-80<br />
5 10 15 20<br />
Radiator<br />
Température<br />
Temp.<br />
Foil (°C)<br />
(°C)
Radiative condenser described in <strong>CFD</strong><br />
3 Dimensions virtual reality description<br />
Convective heating for every shapes and for various wind<br />
speeds is given <strong>by</strong> Iterative calculation<br />
Radiative cooling power E R is dissipated for each radiator<br />
cell. T RAD (one phase model as in dry air)<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
Volumes Grid (<strong>CFD</strong>)<br />
P T ρ<br />
u v w<br />
E R<br />
Shape<br />
Materials<br />
Radiative<br />
cooling<br />
LOG Wind<br />
Profile<br />
Convective<br />
heating
Cone-shaped condenser simulation<br />
Wind speed variations for 0.25 ; 0.5 ; 1.0 and 2.0 m/s at 10 m<br />
side tilt variations for 50 ; 40 ; 35 ; 30 ; and 25 Deg.<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Studied <strong>by</strong> Computational<br />
WIND<br />
Fluid Dynamic<br />
(<strong>CFD</strong>)<br />
PROFILE
Cone-shaped condenser simulation<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
30° tilted<br />
Studied <strong>by</strong> Computational Fluid More Dynamic efficient<br />
(<strong>CFD</strong>)
Cone-shaped condenser prototype (France)<br />
30° tilted<br />
7.3 m², Φ 3 m<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
(<strong>CFD</strong>)<br />
3.160 L water / night<br />
38 % more water than on<br />
the 1m² planar condenser
<strong>CFD</strong> simulations validation<br />
Comparison of simulated efficiency with physical<br />
measurements on real system on 5 various condensers<br />
from 0.16 to 255 m² installed during long period<br />
<strong>Radiation</strong>-<strong>cooled</strong> 1 m² planar condenser <strong>Dew</strong> is the <strong>Water</strong> reference <strong>Condensers</strong><br />
because<br />
Studied always set <strong>by</strong> up simultaneously Computational near<strong>by</strong> Fluid each system Dynamic<br />
(<strong>CFD</strong>)
Radiative condenser as thermal machine<br />
0.16 m²<br />
1 m² REF<br />
7.3 m²<br />
30 m²<br />
(A)<br />
(B)<br />
(C)<br />
(D)<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
(<strong>CFD</strong>)<br />
(E)<br />
3 ridges<br />
255 m²
Comparison “Temperature gain” / “<strong>Dew</strong> gain”<br />
Surface Temperature T COND,<br />
Simulations rough results<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
Non quantitative<br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
(<strong>CFD</strong>)<br />
comparison, the cooler<br />
the surface, the better<br />
the dew yield.
Comparison “Temperature gain” / “<strong>Dew</strong> gain”<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
1 m² 30° 0.16 m 2 30 m², 30°<br />
7.32 m² 3 ridges,<br />
tilted PMMA tilted<br />
cone 255 m²<br />
planar plate planar<br />
<br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
1.00 0.65 1.05 1.40 1.15<br />
1.00 0.68 0.91 1.38 0.81<br />
(<strong>CFD</strong>)<br />
“Cooling power” or “temperature<br />
gain” related with Ta and 1 m² REF:<br />
T<br />
0<br />
T<br />
<br />
T<br />
cond<br />
Re f<br />
T<br />
T<br />
a<br />
a<br />
“<strong>Dew</strong> gain” related to 1 m² REF<br />
condenser water volume.<br />
H 0<br />
H<br />
H<br />
COND<br />
REF
Comparison “Temperature gain” / “<strong>Dew</strong> gain”<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
1 m² 30° 0.16 m 2 30 m², 30°<br />
7.32 m² 3 ridges,<br />
tilted PMMA tilted<br />
cone 255 m²<br />
planar plate planar<br />
<br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
1.00 0.65 1.05 1.40 1.15<br />
1.00 0.68 0.91 1.38 0.81<br />
(<strong>CFD</strong>)<br />
“Cooling power” or<br />
1<br />
“temperature<br />
m² 30°<br />
gain” related with Ta and 1 m² REF:<br />
T<br />
0<br />
T<br />
<br />
T<br />
cond<br />
Re f<br />
tilted<br />
T<br />
T<br />
a<br />
a<br />
0.16 m 2<br />
PMMA<br />
“<strong>Dew</strong> 30 m², gain” 30° 7.32 related m² to 13 m² ridges, REF<br />
tilted condenser cone water volume. 255 m²<br />
1.00 0.65 1.05 1.40 1.15<br />
H(<br />
mm)<br />
<br />
H<br />
H<br />
COND<br />
1.00 0.68 0.91 1.38 0.81<br />
REF
Comparison “Temperature gain” / “<strong>Dew</strong> gain”<br />
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong><br />
1 m² 30° 0.16 m 2 30 m², 30°<br />
7.32 m² 3 ridges,<br />
tilted PMMA tilted<br />
cone 255 m²<br />
planar plate planar<br />
<br />
Studied <strong>by</strong> Computational Fluid Dynamic<br />
1.00 0.65 1.05 1.40 1.15<br />
1.00 0.68 0.91 1.38 0.81<br />
(<strong>CFD</strong>)<br />
“Cooling power” or<br />
1<br />
“temperature<br />
m² 30°<br />
gain” related with Ta and 1 m² REF:<br />
T<br />
<br />
T<br />
tilted<br />
T<br />
0.16 m 2<br />
PMMA<br />
“<strong>Dew</strong> 30 m², gain” 30° 7.32 related m² to 13 m² ridges, REF<br />
tilted condenser cone water volume. 255 m²<br />
1.00 0.65 1.05 1.40 1.15<br />
cond a<br />
COND<br />
0<br />
H(<br />
mm)<br />
<br />
TRe<br />
f<br />
1.00 Ta<br />
0.68 0.91 1.38 H<br />
REF0.81<br />
H
Conclusion<br />
INDIA<br />
Little set of data is needed to<br />
conclude the validation of the<br />
program<br />
This program has been<br />
advantageously used in <strong>Dew</strong><br />
factory project for orientation and<br />
yields prospective<br />
Next step is to develop a two<br />
phases dew condensation<br />
simulation for more accurate<br />
quantitative results
<strong>Radiation</strong>-<strong>cooled</strong> <strong>Dew</strong> <strong>Water</strong> <strong>Condensers</strong> Studied<br />
<strong>by</strong> Computational Fluid Dynamic (<strong>CFD</strong>)<br />
CONTACT : http://www.opur.u-bordeaux.fr/<br />
Owen CLUS
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