Combined gas and steam turbine power plant

摘要

The power plant compresses slightly more air than what is used in stoichiometric combustion and then, or during the infeed of solar or low temperature heat, condensate and/or water is injected into the compressed combustion air, in order to minimise the temperature of the air and condensate. The mixture is determined by the saturated steam temperature due to the increasing partial pressure of the water vapour in the compressed air. In this way the highest possible heat input at low temperature is achieved. The requisite gas turbine entry temperature is maintained for stoichiometric combustion and the mix or compressed combustion air and steam is preheated on solar and/or low temperature heat so as to raise the mixture temperature above the steam partial pressure for the corresponding saturated steam temperature. If heat input fails during these stages, the turbine entry temperature is regulated by reducing the condensate and/or water injection and increases air input and the excess air as a result.