Ex.2 A liquid flat plate collector has the following characteristic parameters F (ra)=0.68; FU, -6.1 W/m-K It is operating under the following conditions: Solar flux incident on the collector plane: 900 W/m Water flow rate: 0.015 kg/s-m of the absorber area Ambient temperature: 20 C Inlet water temperature:40 C i. ii. Calculate the mean absorber plate temperature of the collector, if the collector efficiency factor is 0.90. If the circulating pump fails what is the maximum temperature attained by the plate. SOLUTION SOLUTION q = AS-U,A,(T-T) pm Hottel-whillier-Bliss equation |q = FRA, [S-U, (T-T)] qu mC F'U,A FR = U,A P 1-exp mC P