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Unformatted text preview: UNIVERSITY OF FLORIDA 1 Solar Utilization ( 29 [ ] a pm L c u T T U S A Q = energy useful Q u = area collector A c = e temperatur ambient T e temperatur absorber plate mean T t coefficien loss heat overall U area unit per absorbed radiation solar S a pm L = = = = ) (  = T a in f L av R c I T T U K F ) ( ) ( , τα η τα HottelWhillier Equation: We need to get from there to here ifier angle incidence K in fluid of e temperatur T collector on incident radiation solar total I factor removal heat collector F absorb and trans glass of product efficiency collector in f T R c mod . . , = = = = = = τα τα η Eqn. 1 Eqn. 2 UNIVERSITY OF FLORIDA 2 Solar Utilization ( 29 [ ] a pm L c u T T U S A Q = energy useful Q u = area collector A c = e temperatur ambient T e temperatur absorber plate mean T t coefficien loss heat overall U area unit per absorbed radiation solar S a pm L = = = = ) ( An energy balance for a flat plate solar collector where U L is defined based on the temperature difference given. T pm is very difficult to measure. We will develop a form of Q u in terms of measureable terms and then we can use Q u to estimate the collector efficiency, η c. We’ll need to also have a way of determining I T , the total radiation incident on the solar collector surface. T c u c I A Q = η Eqn. 1 Eqn. 3 UNIVERSITY OF FLORIDA 3 Solar Utilization s s s s north b R δ φ ϖ δ φ δ β φ ϖ δ β φ sin sin cos cos cos sin ) sin( cos cos ) cos( , + + =  + + + = 2 cos 1 2 cos 1 β ρ β g d b b T I I R I I The total solar radiation incident on the collector surface, I T....
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 Fall '08
 Staff
 Energy, Heat, Light, Trigraph, Solar Utilization

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