Combined cycle power plant

Abstract

The invention relates to a combined cycle power plant that includes, a gas turbine plant, a heat recovery steam generator heated by hot waste gases of a gas turbine plant, and a steam turbine plant driven by the steam produced, and a waste gas purification plant, arranged downstream of the heat recovery steam generator in which carbon oxides in the waste gases can be absorbed by an absorber fluid, which is subsequently regenerated at an elevated temperature in a regenerating section while giving up the carbon oxides for supplying to a storage. The regenerating section has a heater for maintaining a necessary elevated temperature for regeneration. The heater operates with steam from the heat recovery steam generator or from the steam turbine plant. The steam condenses and the resulting hot condensate can be supplied to a flash boiler where it, at low pressure, immediately at least partially evaporates. This steam can be supplied to an appropriate stage of the steam turbine plant according to the steam pressure.

1 . A combined cycle power plant (CCPP) comprising,
 a gas turbine plant,   a heat recovery steam generator through which hot waste gases from the gas turbine plant flow,   a steam turbine plant driven by steam from the heat recovery steam generator, and   a waste gas purification plant, arranged downstream of the heat recovery steam generator, having an absorbing section in which carbon dioxide in the waste gases is absorbed by an absorber fluid, whereby the waste gas purification plant comprises a regeneration section which is supplied with the absorber fluid loaded with carbon dioxide, whereby the absorber fluid can be regenerated at an elevated temperature while giving up the carbon dioxide for supplying to a storage, and whereby the regenerated absorber fluid is supplied back into the absorbing section for absorbing the carbon dioxide in the waste gases, whereby the regeneration section comprises a heater which is heatable with the steam from the heat recovery steam generator or from the steam turbine plant, whereby the supplied steam condenses in or at the heater and the resulting hot condensate is supplied to at least one evaporator, where it is at least partially evaporated to steam and whereby this steam is introduced into a stage of the steam turbine plant, in particular into an intermediate stage of the low pressure turbine of the steam turbine plant.   
     
     
         2 . The combined cycle power plant according to  claim 1 , further comprising a heat exchanger is arranged between the absorber section and the regeneration section, whereby the absorber fluid from the regeneration section being led back into the absorbing section, and the absorber fluid from the absorbing section being supplied to the regeneration section through the heat exchanger. 
     
     
         3 . The combined cycle power plant according to  claim 1 , wherein the thermal energy extracted from the absorbing section is used for preheating fuel for the gas turbine plant or for preheating feed water for the steam turbine plant. 
     
     
         4 . The combined cycle power plant according to  claim 1 , wherein a part of the steam generated by the at least one evaporator is added to the steam supplied to the heater of the regeneration section. 
     
     
         5 . The combined cycle power plant according to  claim 1 , wherein the steam generated by the at least one evaporator is superheated in a heater of the heat recovery steam generator and then supplied to a middle stage of the low pressure turbine of the steam turbine plant. 
     
     
         6 . The combined cycle power plant according to  claim 1 , wherein the steam turbine plant comprises a high pressure steam turbine, a medium pressure steam turbine and a low pressure steam turbine, whereby steam is taken from a point between the outlet of the medium pressure steam turbine and the inlet of the low pressure steam turbine for heating the heater of the regeneration section. 
     
     
         7 . The combined cycle power plant according to  claim 1 , wherein the condensate is supplied to a cascade of flash boilers, whereby pressurized water or condensate from a first flash boiler is supplied to a second flash boiler which has a lower inner pressure relative to the first flash boiler, so that the pressurized water or condensate from the first flash boiler can at least partially evaporate, whereby the steam produced by the flash boilers is supplied to one or more stages of the steam turbine plant, in particular to the low pressure steam turbine, corresponding to their different pressures. 
     
     
         8 . The combined cycle power plant according to  claim 7 , wherein the steam from the at least one flash boiler is superheated, e.g. with the heat recovery steam generator, before being introduced into a stage of the steam turbine plant. 
     
     
         9 . The combined cycle power plant according to  claim 7 , wherein the steam from the at least one flash boiler is superheated by the steam, coming from the outlet of the high pressure steam turbine of the steam turbine plant. 
     
     
         10 . The combined cycle power plant according to  claim 1 , wherein the remaining condensate from the at least one evaporator is supplied to the feed water tank of the steam turbine plant.