Improvement of the tilted wick solar still by using a flat plate reflector

146
6. Symbols
G df — Diffuse solar radiation, W/m 2
G dr — Direct solar radiation, W/m 2
l m — Height of reflector, m
l s — Length of still, m
mc p — Heat capacity, J/K
m f — Feed rate of saline water, kg/m 2 s
Q c — Convective heat transfer rate, W
Q d — Conductive heat transfer rate, W
Q e — Heat transfer rate of evaporation and
condensation, W
Q f — Enthalpy increase of feeding saline
water, W
Q r — Radiative heat transfer rate, W
Q sun,df — Absorption of diffuse solar radiation,
W
Q sun,dr — Absorption of direct solar radiation,
W
Q sun,g — Absorption of solar radiation on
glass cover, W
Q sun,re — Absorption of reflected solar radiation,
W
Q sun,w — Absorption of solar radiation on
wick, W
T — Temperature, K
t — Time, s
w — Width of still, m
Greek
α — Absorptivity
β — Incident angle
φ — Solar altitude angle
γ — Azimuth angle of still
ϕ — Solar azimuth angle
θ — Angle of still
ρ re — Reflectivity of reflector
τ g — Transmissivity of glass cover
Subscripts
a — Ambient air
H. Tanaka, Y. Nakatake / Desalination 216 (2007) 139–146
g — Glass cover
w — Wick
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