Answer:
The thermal efficiency of the Rankine cycle can be calculated using the formula:
$\eta_{th}=\frac{(h_1-h_2)-(h_4-h_3)}{(h_1-h_4)}$
where:
h1 = enthalpy at turbine inlet
h2 = enthalpy at turbine outlet
h3 = enthalpy at condenser inlet
h4 = enthalpy at condenser outlet
Given:
- The enthalpy decrease in the turbine is 150 kJ/kg (h1 - h2 = 150 kJ/kg)
- The heat released during condensation is 280 kJ/kg (h1 - h4 = 280 kJ/kg)
Assuming the pump work is negligible, we can simplify the efficiency equation:
$\eta_{th}=\frac{(h_1-h_2)}{(h_1-h_4)}=\frac{150}{280}=0.536$
Therefore, the thermal efficiency of the Rankine cycle is 53.6%.