ME 5300 MT
NAME: q,
The solar collector shown consists of a glass cover plate, a collector plate, and side walls. Assume that the glass is completely transparent to solar irradiation, which penetrates through the glass and hits the absorber plate with a flux of 1000(W)/(m^(2)). The absorber plate is black and is kept at a constant temperature of T1=77\deg C by heating water flowing underneath it. The side walls are insulated and made of a material having emissivity 0.5 . The glass cover is opaque to thermal IR radiation with an emissivity of 0.9 . The collector is 1 mX 1 mX 10 cm and is evacuated such that free convection between the absorber plate and glass cover is non-existent. The heat transfer coefficient at the top of the glass cover to the ambient is h=5(W)/(m^(2))-K, and the temperature of the ambient is T_(a)=17\deg C. Assume that the sky radiates to the collector with the ambient temperature.
a. Draw the correct thermal resistance network
b. Determine the temperature of the side walls T_(2)(\deg C)
c. Determine the temperature of the glass cover T_(3)(\deg C)
d. Compute the collected energy ( W ) for normal solar incidence
e. Compute the efficiency (%) of the collector
f. Compare e. to that of an uncovered black plate