Combined cycle power plant and method for operating such a combined cycle power plant

• Main Authors: Couzzicarneiro, Mariah, Dietzmann, Joerg
• Format: Patent
• Language: English
• Published: 09.02.2021
• Subjects: AIR INTAKES FOR JET-PROPULSION PLANTS; BLASTING; COMBUSTION ENGINES; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DYNAMO-ELECTRIC MACHINES; ELECTRICITY; ENGINE PLANTS IN GENERAL; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES; GAS-TURBINE PLANTS; GENERATION; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAMTURBINES; STEAM ACCUMULATORS; STEAM ENGINE PLANTS; STEAM ENGINES; WEAPONS

A water/steam system for a combined cycle power plant and related method for operating said system are provided. The system comprises a heat recovery steam generator providing a flue gas stream path for extracting heat from a flue gas stream exhausted from a gas turbine, the heat recovery steam generator having a low pressure section including a low pressure evaporator arranged along the flue gas stream path for generating low pressure steam at a low pressure input level for a main input of a low pressure steam turbine. To use heat at low temperatures, the low pressure section may include a sub low pressure subsection with a sub low pressure evaporator for generating sub low pressure steam, at a sub low pressure level below the low pressure input level. The sub low pressure evaporator is disposed in the flue gas stream path downstream of a low pressure economizer.