Abstract: A system using hybrid Rankine cycles is provided. The system includes a first Rankine cycle system using a first working fluid, the first system producing exergy loss and residual energy from at least one of turbine extraction, turbine condensation and boiler flue gas; and a second Rankine cycle system using a second working fluid to recover the exergy loss and residual energy. The second working fluid comprises a first stream and a second stream, wherein the first stream exchanges heat with the first system via at least one first heat exchanger, and the second stream exchanges heat with the first system via the at least one first heat exchanger and at least one second heat exchanger. A turbine of the first system is configured to allow the first working fluid to exit at a sufficiently high pressure and temperature to provide heat to the second system instead of expanding to a low pressure and temperature and discharging heat to ambient using a condenser.

Abstract: A system using hybrid Rankine cycles is provided. The system includes a first Rankine cycle system using a first working fluid, the first system producing exergy loss and residual energy from at least one of turbine extraction, turbine condensation and boiler flue gas; and a second Rankine cycle system using a second working fluid to recover the exergy loss and residual energy. The second working fluid comprises a first stream and a second stream, wherein the first stream exchanges heat with the first system via at least one first heat exchanger, and the second stream exchanges heat with the first system via the at least one first heat exchanger and at least one second heat exchanger. A turbine of the first system is configured to allow the first working fluid to exit at a sufficiently high pressure and temperature to provide heat to the second system instead of expanding to a low pressure and temperature and discharging heat to ambient using a condenser.