SECOND-LAW ANALYSIS OF REHEAT AND REGENERATIVE STEAM POWER CYCLES.

The application of the second law of thermodynamics, in conjunction with the first law, to the reheat and regenerative versions of the steam power cycle is demonstrated. The reheat cycle consists of an HP turbine, while the regenerative cycle includes an open heater and a closed heater. The calculations indicate that reheating decreases the first-law efficiency slightly, but leaves the second-law efficiency unchanged; regeneration improves the first-law efficiency more than the second-law efficiency. The enthalpy and availability distribution diagrams for the two cases have been plotted as Sankey diagrams which illustrate the various energy and availability flows.