How is heat rejected in the Rankine cycle typically accomplished?

In the Rankine cycle, heat rejection is typically accomplished at a constant pressure. This is a key characteristic of the cycle’s operation. When the working fluid, usually water, exits the turbine and is sent to the condenser, it is at a low temperature and pressure. In the condenser, the fluid rejects heat to a cooling medium, usually water or air, at a constant pressure while undergoing a phase change from vapor to liquid. This phase change is crucial as it allows the fluid to release a significant amount of heat without a change in pressure, which effectively facilitates efficient cooling and prepares the fluid to be pumped back into the boiler.

Maintaining a constant pressure during heat rejection ensures the system operates efficiently and enhances the overall thermodynamic cycles. Variations in pressure during this process would result in reduced efficiency and complications in heat transfer, as the thermodynamic principles governing the cycle are based on fixed pressure conditions.