PROCESS FOR SEAWATER DESALINATION AND ELECTRIC POWER GENERATION AT A COMBINED PLANT

摘要

The effective work of a gas turbine unit is used for electric power generation. Overheated steam generated in a waste heat boiler (6) is expanded in a back pressure steam turbine (4) with controlled extraction of 1.3 MPa and an exhaust pressure of 0.125 MPa. Steam from the steam turbine (4) controlled extraction is fed to a steam ejector (11) as injecting steam; steam from the last stage of a multi-stage evaporator is fed to a mixing chamber. Seawater is first heated in heat exchangers (17) of the evaporator stages, then heated to 95-98°C in a heat exchanger of the evaporator first stage using heating steam from the steam turbine back pressure. This is followed by its additional heating to 100-102°C in external heat exchangers (16), (18) using the heat of heating steam and of steam from the steam ejector. Steam condensate with a high salt content from all the evaporator stages is pooled and discharged to the initial seawater. Most of the secondary steam condensate is forwarded to consumers. Its smaller portion is purified from salts by means of chemical water treatment, deaerated and used as additional feed water in the waste heat boiler.