GB718176A - Improvements in or relating to mixed power plants incorporating tubulous vapour generators - Google Patents

Abstract

718,176. Power plants; water-tube steam boilers. BABCOCK & WILCOX, Ltd. Oct. 8, 1951 [Oct. 9, 1950], No. 24595/50. Classes 123(2) and 123(3) A steam-boiler, Figs 2 and 3, comprises a pair of separately-fired combustion chambers 21, 22 which are separated by a refractory-covered tube wall 23, the tubes of the latter extending between a lower header 24 and an upper steam-and-water drum 25, and are bounded by steamgenerating tube banks 26, 30 through which combustion gases flow, respectively, direct to an uptake 28 and through a passage 33 at the rear of the boiler also to said uptake. The tube bank 26 is divided by a baffle wall 45 into sections 43, 44 through which gases from the chamber 21 flow in parallel under the control of dampers 53 at the respective exits of the gas flow paths, and a superheater 48 is located within the section. 43. The tube bank 30) is relatively shallow, and beyond it there is provided a two-part air-heater 61, 62. Further shallow banks 68, 71 of steamgenerating tubes extending from the drum 25 to the lower drums 27, 31 of the tube banks 26, 30 are disposed within the passage 33. The boiler 7, 8, 9, Fig. 1, is intended for a mixed power plant comprising steam and gas turbines 1, 3, the latter being supplied with gas from, and driving, an air compressor 13 which forces 'air successively through the air heater 14 (61, 62) and a chamber 15 in which a small quantity of fuel is combusted. The exhaust from the steam turbine is condensed at 10 and returned to the boiler, and that from the gas turbine provides. combustion air for the boiler burners 17 (88, 89). An internal combustion engine 2 may also be incorporated in the plant, the engine being cooled by the condensate from the steam turbine and the exhaust therefrom being discharged into the boiler passage 33 through a conduit 70. The air supply from the air turbine to the wind-boxes 90, 91 of the burners 88, 89 is controlled by dampers 94, 95 respectively, and, during operation of said turbine, a pressure is maintained within the outer wall 100 of the boiler at least equal to the pressure within the wind-boxes by means of a fan which may also be used, if necessary, for supplying air to the burners and air-heater. Specification 718,259 is referred to.