A steam power plant with a low-pressure turbine is suggested with a second low-pressure turbine on a separated shaft line including a separate generator. The second low-pressure turbine is connected to an additional condensing system without cooling water consumption, thus allowing to maintain the power output at a high level, even if the main condensing system has a reduced capacity due to cooling water restrictions.

A steam power plant with a low-pressure turbine is suggested with a second low-pressure turbine on a separated shaft line including a separate generator. The second low-pressure turbine is connected to an additional condensing system without cooling water consumption, thus allowing to maintain the power output at a high level, even if the main condensing system has a reduced capacity due to cooling water restrictions.

A steam power plant and method for operation the steam power plant is provided, that comprises: a main water-steam-cycle with a high pressure (HP) steam turbine, an intermediate pressure (IP) steam turbine and a low pressure (LP) steam turbine, a condenser, and a feed water tank, wherein low pressure heaters are arranged between said condenser and said feed water tank and wherein a plurality of high pressure heaters are arranged downstream of said feed water tank, whereby said low pressure heaters, said feed water tank and said plurality of high pressure heaters are supplied with steam from a plurality of extractions at said steam turbines.

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.

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.

A steam power plant is suggested having, parallel to the high-pressure preheater passage (VW4 to VW6), a heat reservoir (A) which is loaded with preheated condensate in weak-load times. This preheated condensate is taken from the heat reservoir (A) for generating peak-load and inserted downstream of the high-pressure preheater passage (VW4 to VW6) into the condensate line (19.2) resp. the feed water container (8). Thus it is possible to quickly control the power generation of the power plant in a wide range without significantly having to change the heating output of the boiler of the steam generator (1). A steam power plant equipped according to the invention can thus be operated with bigger load modifications and also provide more control energy.

A steam power plant is suggested having, parallel to the high-pressure preheater passage (VW4 to VW6), a heat reservoir (A) which is loaded with preheated condensate in weak-load times. This preheated condensate is taken from the heat reservoir (A) for generating peak-load and inserted downstream of the high-pressure preheater passage (VW4 to VW6) into the condensate line (19.2) resp. the feed water container (8). Thus it is possible to quickly control the power generation of the power plant in a wide range without significantly having to change the heating output of the boiler of the steam generator (1). A steam power plant equipped according to the invention can thus be operated with bigger load modifications and also provide more control energy.

A hybrid power generation system using a supercritical CO.sub.2 cycle includes a steam power generation unit including a plurality of turbines driven with steam heated using heat generated by a boiler to produce electric power, and a supercritical CO.sub.2 power generation unit including an SCO.sub.2 heater for heating a supercritical CO.sub.2 fluid, a turbine driven by the supercritical CO.sub.2 fluid, a precooler for lowering a temperature of the supercritical CO.sub.2 fluid passing through the turbine, and a main compressor for pressurizing the supercritical CO.sub.2 fluid, so as to produce electric power. The steam power generation unit and the supercritical CO.sub.2 power generation unit share the boiler. The hybrid power generation system may improve both the power generation efficiencies of the steam cycle and the supercritical CO.sub.2 cycle by interconnecting the steam cycle and the supercritical CO.sub.2 cycle.

A hybrid power generation system using a supercritical CO.sub.2 cycle includes a steam power generation unit including a plurality of turbines driven with steam heated using heat generated by a boiler to produce electric power, and a supercritical CO.sub.2 power generation unit including an SCO.sub.2 heater for heating a supercritical CO.sub.2 fluid, a turbine driven by the supercritical CO.sub.2 fluid, a precooler for lowering a temperature of the supercritical CO.sub.2 fluid passing through the turbine, and a main compressor for pressurizing the supercritical CO.sub.2 fluid, so as to produce electric power. The steam power generation unit and the supercritical CO.sub.2 power generation unit share the boiler. The hybrid power generation system may improve both the power generation efficiencies of the steam cycle and the supercritical CO.sub.2 cycle by interconnecting the steam cycle and the supercritical CO.sub.2 cycle.

In a system for effecting pressure control in a thermal power plant operated at low load connected fluidly in series, a relief conduit is disclosed herein. The relief conduit selectively transfers steam from a cold reheat conduit to the second extraction conduit. The plant further includes a boiler, a high-pressure turbine, an intermediate pressure turbine, a low pressure turbine, a main steam conduit for feeding steam from the boiler to an inlet of the high pressure turbine, a cold reheat conduit for feeding steam from an outlet of the high-pressure turbine through a reheat flow path in the boiler, and a first and second high pressure heaters. A first extraction conduit connects the cold reheat conduit to a first high pressure heater to transfer heat, and a second extraction conduit connects the intermediate pressure turbine to the second high pressure heater, to transfer heat.