GB575935A - Steam power plant with particularly high superheating temperatures - Google Patents

Abstract

575,935. Steam superheaters. AKT.-GES. BROWN, BOVERI, & CIE. Dec. 22, 1943, No. 21489. Convention date, Dec. 22, 1942. [Class 123 (iii)] Steam is superheated in two stages, first to a temperature considerably below 500‹ C. in the superheater 2 of the steam boiler 1, and then up to an operating temperature considerably above 500‹ C. in a separately fired superheater 12 heated by hot gases coming from a pressure-fired combustion chamber 14 and passing along the heating surfaces of the superheater at a very high velocity as a result of a pressure gradient produced by a compressor 15 driven by a turbine 18 the motive gases of which are the hot gases from the superheater 12. In the form shown, the compressor 15 supplies air under pressure to the combustion chamber 14, and a reheater 13 is associated with the superheater 12 which receives steam direct from the superheater 2. Steam from the superheater 2 may however be used in at least one turbine stage before the second stage of superheating is performed. An auxiliary electric motor or steam turbine 19 starts and helps to drive the compressor 15. The motor or turbine 19 may be used to regulate the speed of the compressor. To moderate the temperature of the combustion gases from the chamber 14, some of the gases leaving the reheater 13 are returned by a blower 20 to mix with the hot combustion gases. The exhaust gases from the turbine 18 may be passed to the steam generator, or used to heat the feedwater or the air supplied to the chamber 14. Feedwater is also heated in the heaters 22 by exhaust steam from the turbines.