A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature of 350°C and the Condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle?
A. 7.7
B. 17.7
C. 27.7
D. 37.7
Answer:A
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature of 350°C and the Condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle?
A. 7.7 B. 17.7 C. 27.7 D. 37.7
Explanation: Fixing the states; h1 = 340.5 kJ/kg, h2 = h1 + v1 (P2 – P1) = 343.5 kJ/kg, h3 = 3115.3 kJ/kg, s3 = 6.7428 kJ/kg – K, x4 = 0.869, and h4 = 2343.9 kJ/kg. Thus, η = 1 – Qout / Qin = 1 – (h4 – h1) / (h3 – h2) = 27.7%.