STEAM TURBINE PLANT FEED WATER PREHEATING SYSTEM Russian patent published in 1999 - IPC

FIELD: thermal and nuclear power plants. SUBSTANCE: system includes high-and low-pressure preheaters and additional double-stage preheater. First stage of double-stage preheater is made in form of compressor whose suction branch pipe is connected with one of last stages of turbine and cooling elements are connected to feed water supply pipe line before low-pressure preheater; second stage includes pump and jet apparatus arranged in series in way of motion of feed water; pump is connected to fed water pipe line after last high-pressure preheater; working nozzle of jet apparatus is made in form of Laval nozzle; outlet hole of Laval nozzle diffuser is located in prechamber mounted additionally before mixing chamber of jet apparatus; prechamber is connected by means of pipe line with system discharging steam from turbine for compression; mixing chamber is connected with compressed steam pipe line. Angle of opening of Laval nozzle diffuser is equal to 4-5 deg; length of diffuser is determined by ratio of areas of outlet hole section and neck which is equal to 4-5; swirling device fitted before Laval nozzle neck provides for obtaining lesser angle of opening of liquid jet by 1 to 2 deg as compared with angle of opening on Laval nozzle. EFFECT: increased degree of using heat of phase transition of waste steam for preheating feed water. 2 cl, 2 dwg