GB652925A - Improvements in and relating to steam power plants - Google Patents

Abstract

652,925. Power-generating systems; steam turbines. FIELD, J. F. Jan. 13, 1948, No. 994. [Classes 110(iii) and 122(iii)] A steam power plant includes one or more externally fired superheaters 5, 6 each followed by a steam turbine 16, 17, a surface steam to steam heat exchanger 26, a steam bleed-off pipe 36 leading either to a steam heating system for process or to a further turbine 19 arranged for condensing and feed heating, a direct water injection desuperheater 22 and a single or multistage compressor 15, the turbine and compressor elements being mechanically coupled. Outlet steam from the compressor 15 in an approximately dry saturated condition is heated in the high pressure side of the heat exchanger 26, further heated in the superheater 5, expanded in the turbine 16, reheated in the second superheater 6, expanded in the second turbine 17 and passed through and deprived of heat in the low pressure side of the heat exchanger 26; a quantity of the steam is then bled off either to the further turbine 19 which drives a generator 20 or to process and the main stream is further cooled in a feed water heater 38 and then made sufficiently wet by the direct injection therein in the desuperheater 22 of a fine spray of preheated feed water, from the condenser 35 of the turbine 19 or other source, substantially equal in weight to the amount of bled steam, so that it may be finally compressed in the compressor 15 to its original dry saturated high pressure condition. Alternatively, the quantity of water beyond that required to render the inlet steam to the compressor 15 dry saturated may be injected into the compressor stage by stage or injected at the compressor outlet. Combustion air for the superheater furnace 1 is supplied by a fan 10, preheated in an air preheater 7 and exhausted by an induction fan 11.