3. An engineering firm has been contracted for the design of a parabolic trough solar-thermal power plant. If you were hired as the thermal design engineer, please perform an analysis and find what is the maximum possible working fluid (oil) exit temperature? The optimal pipe length is equal to that when the oil exit temperature reaches 95% of the maximum possible temperature. What is the optimal pipe length ? Please explain why the temperature of the oil would not increase after the maximum temperature is reached? Plant design information: Working fluid: Therminol VP-1 oil (eutectic mixture of 73.5% Diphenyl ether and 26.5% Biphenyl), specific heat is 2436 J/kgK. System parameters: m=0.03kg/s,h=50W/mK,K=0.6W/mK, L, = 0.01m, h=12W/mK, K = 36W/m K, L, -0.005m, h = 60W/mK. Collector Tube equivalent width = 0.1m. G = 200W/m, concentration ratio=16 Ta=0.8, cos0=1,T=30C,T=25C. gas enclosure or vacuum oil absorber layer -Insulation glass cover T oil TE Equivalent width =0./m W Jas enclosure Tabsorber layer glass Cover Equivant Rectangular Geometry reflector Coolant pipe Parabolic trough schematic