Determine the equilibrium temperature of the absorber surface in Prob. 12–98 if the back side of the absorber is insulated.

Data from problem 98

The absorber surface of a solar collector is made of aluminum coated with black chrome (α_s = 0.87 and ε = 0.09). Solar radiation is incident on the surface at a rate of 600 W/m². The air and the effective sky temperatures are 25°C and 15°C, respectively, and the convection heat transfer coefficient is 10 W/m² · K. For an absorber surface temperature of 70°C, determine the net rate of solar energy delivered by the absorber plate to the water circulating behind it.

Transcribed Image Text:

↓↓↓ Sun Gsolar = 600 W/m² Tair = 25°C Tsky = 15°C -T, = 70°C Absorber plate Water tubes Insulation