A method for increasing the efficiency of multistage feed-water heating by extractedsteam

摘要

854,410. Feedwater heating systems. NEKOLNY, J. Feb. 1, 1957 [June 11, 1956], No. 3583/57. Class 64(1) A feedwater heating system for steam turbines comprises a series of condensation heaters 7, 8 9 and 10 in which condensate from the condenser 2 is heated by tapped steam from a turbine 1 and is characterized by the superheated steam from at least one of the extraction points of the turbine being passed through the secondary circuit of a precooler 16 whose primary circuit is fed by the main flow of condensate or by the condensate from one of the condensation heaters. The steam from two extraction points 3, 4 may be passed through the precooler as shown in Fig. 1 or a series of precoolers 16, 17 and 18 may be used as shown in Fig. 2 in which case the steam may pass through two precoolers before being fed to a condensation heater. In a modification, by the provision of additional banks of tubes in the condensation heaters the steam may be further cooled by being passed through these heaters from the precooler. In further modifications the primary circuit of the precooler may be fed by passing either a small quantity of the main flow of condensate through it, or the condensate from one of the condensation heaters.