Explain the Rankine cycle and how to improve its efficiency.

The Rankine cycle is the ideal cycle for steam power plants, consisting of isentropic compression in pump, constant-pressure heat addition in boiler, isentropic expansion in turbine, and constant-pressure heat rejection in condenser. Efficiency can be improved by increasing boiler pressure, increasing superheat temperature, lowering condenser pressure, using reheat cycles, and implementing regenerative feedwater heating. Modern supercritical plants achieve efficiencies above 45%.