A solar collector consists of a parallel plate channel that is connected to a water storage plenum at the bottom and to a heat sink at the top. The channel is inclined 0 = 30° from the vertical and has a transparent cover plate. Solar radiation transmitted through the cover plate and the water maintains the isothermal absorber plate at a temperature

Ts = 67°C, while water returned to the reservoir from the heat sink is at T_∞ = 27°C. The system operates as a thermosyphon for which water flow is driven exclusively by buoyancy forces. The plate spacing and length are S = 15 mm and L = 1.5 m. Assuming the cover plate to be adiabatic with respect to convection heat transfer to or from the water, estimate the rate of heat transfer per unit width normal to the flow direction (W/m) from the absorber plate to the water.

Transcribed Image Text:

To heat sink - Absorber plate, T, Cover plate Plenum Water From heat sink