COMBINED CYCLE POWER PLANT AND METHOD FOR OPERATING SUCH A COMBINED CYCLE POWER PLANT

• Main Authors: Dietzmann, Joerg, Couzzi-Carneiro, Mariah
• Format: Patent
• Language: English; French; German
• Published: 20.09.2017
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ACCUMULATORS; STEAM ENGINE PLANTS; STEAM ENGINES; WEAPONS

The invention relates to a water/steam system (1) for a combined cycle power plant, comprising a heat recovery steam generator (4) providing a flue gas stream path (6) for extracting heat from a flue gas stream (9) exhausted from a gas turbine, the heat recovery steam generator (4) having a low pressure section (3) including a low pressure evaporator (13) arranged along the flue gas stream path (6) for generating low pressure steam at a low pressure input level (p 10 ) for a main input (54) of a low pressure steam turbine (51). Furthermore, the invention relates to a method for operating such a water/steam system (1). In order to use heat a low temperatures, the present invention provides that in the low pressure section () additionally sub low pressure steam at a sub low pressure level (p 11 ) below the low pressure level (p 10 ) is generated by means of a sub low pressure evaporator (23) in the flue gas stream path (6).