GB334473A - - Google Patents

Abstract

334,473. Akt.-Ges. Brown, Boveri, et Cie. Dec. 24, 1928, [Convention date]. Heating machines whilst inoperative; dynamos, cooling. - An electric turbo-generator is maintained at the working temperature whilst inoperative so as to be ready to take on full load by supplying heat from an outside source by means of a gaseous heat carrier, such as air, which is kept continuously in circulation. Fig. 3 shows a turbo-generator 9 embodying the usual closed cooling system comprising inlet ducts 10, 11, outlet duct 12, a cooler 15 and a blower 14 driven by a motor 13. When the generator is out of operation, the cooler may be employed as a heater by shutting off the cold water valves 16, 17 and opening steam or hot water valves 18, 19. All the valves may be regulated by a thermostat to maintain a constant working temperature whether the machine be in or out of operation. The losses in the blower may supply the necessary heat, the rate of generation of heat being regulated by a thermostat which controls the speed of the driving motor. Instead of using the blower in the ordinary cooling system, a separate auxiliary installation may be provided. An electric resistance 22 in the main cooling ducts may supply the necessary heat or a subsidiary system comprising ducts 24, 25, a blower 27 driven by a steam turbine 26, and an electric heater 23 may be used. The source of heat may be kept in operation continuously. Regulation may be effected by the use of a thermostat 30 built into a pipe 31 in the subsidiary system. The thermostat controls contacts 37 in the circuit of the heating element 23. The turbine 26 also may be controlled by the thermostat, and where a steam heater is used instead of the resistance 23, it may be supplied from the exhaust of the turbine and regulated by a throttle 38. Fig. 4 shows the invention applied to a turbogenerator 45 driven by a steam turbine which also is required to be kept hot whilst inoperative. A common source of heat 40 is employed supplying the turbine through pipes 42 and 43 and blower 44 and supplying the generator through pipes 46, 47 and valves 49, 50. For adjusting the temperature-volume ratios of the two heat carriers, an auxiliary blower 51 with valves 52, 53 may be provided. In the case of very long rotors, they should be rotated slowly while heat is being supplied.