The profitability of a 2 MW Rankine power cycle driven by solar energy is to be investigated. The working fl uid is Freon-12. Freon enters the turbine at 90°C and 2.5 MPa and exits the condenser as a...

The profitability of a 2 MW Rankine power cycle driven by solar energy is to be investigated. The working fl uid is Freon-12. Freon enters the turbine at 90°C and 2.5 MPa and exits the condenser as a saturated liquid at 25°C. The adiabatic effi  ciency of the turbine is 0.8 and of the pump is 1.0. Assume a temperature difference of 5°C for heat transfer in the evaporator (which receives heat from a solar collector) and in the condenser. a. Describe the cycle on a T–s diagram and calculate the points in the cycle (point 1 is at the entrance to the turbine). b. Calculate the efficiency of the cycle and compare with Carnot efficiency c. Calculate the Freon mass fl ow rate. d. Estimate the hourly saving in fuel, if the thermodynamic efficiency of a conventional power plant is 40%, and the caloric value of the fuel is 42,000 kJ/kg.