Improved method of cooling the gas or liquid coolant of a turbo-generator and apparatus therefor

1,035,806. Heating feedwater for boilers; cooling systems for electric generators; gas cooling installations. RICHARDSONS, WESTGARTH & CO. Ltd. Jan. 2, 1963 [Jan. 5, 1962], No. 527/62. Headings F4A, F4S and F4U. The heated gas or liquid coolant for a steam turbine driven, fluid-cooled electric generator is cooled by transferring its heat to boiler feedwater in two or more stages at different temperatures of the coolant. Thus, in Fig. 1, condensate from the turbine condenser 1 passes serially through a steam heater 3a, a first heat exchanger 6 positioned in the generator cooling gas duct 7, a second steam heater 3b wherein the feed water temperature is raised further, and a second heat exchanger 8 which is positioned upstream in the duct 7. In a modification, Fig. 2, part of the condensate from the turbine condenser 24 is evaporated in a heat exchanger 27 in the duct 7, the vapour passing to a heater 20, wherein it is condensed in direct contact with the remainder of the condensate passing directly into this heater, into which steam is also admitted through a line 22. Some of the condensate from the heater 20 passes into a second heat exchanger 28 positioned upstream in the duct 7, wherein it is evaporated, the vapour passing to a second heater 21 wherein it is condensed in direct contact with the remainder of the condensate passing directly into the heater 21, into which steam is also admitted through a line 23. The heat ex. changers comprise normally submerged coils or tubes, and pumps and valves regulate flow through the various components.