Question 5.2: A gas turbine-based combined-cycle operates without suppleme......

1. Power output of the simple-cycle gas turbine power plant

$P_{GT}=\eta_{GT}Q_{i n}=0.4\times600=240~{\mathrm{MW}}$

2. Overall thermal efficiency of the combined-cycle

$\eta_{C C}=\eta_{GT}+\eta_{ST}\left(1-\eta_{GT}\right)=0.4+0.33\times(1-0.4)=0.598$

3. Overall power output of the combined-cycle power plant

$P_{\mathrm{CC}}=\eta_{\mathrm{CC}}Q_{\mathrm{in}}=0.598\times600~{\mathrm{MW}}=358.8~{\mathrm{MW}}$

4. Power output of the bottoming steam power plant

$P_{\mathrm{ST}}=P_{\mathrm{CC}}-P_{\mathrm{GT}}=358.8-240=118.8~\mathrm{MW}$