GB314905A - Improvements in steam generators - Google Patents

Abstract

314,905. Akt.-Ges. Brown, Boveri, et Cie. July 4, 1928, [Convention date]. Heating by indirect contact of gases from explosion chambers.-In a steam boiler comprising means for circulating the boiler water through heat exchangers 4, 6, Fig. 1, through which explosion products from explosions chambers 1-3 flow at high velocity on their way to a gas turbine 8, the frequency of opening of the valves 11-13 controlling the admission of explosive mixture to the chambers 1-3 from a compressor 9 driven by the gas turbine is increased. up to a certain point with decreasing boiler steam pressure, and afterwards the speed of the compressor is increased by bringing into operation another engine such as a steam turbine 19 connected to the compressor shaft. The speed of the water circulation pump 14 between the heat-exchangers. and the boiler drum 15 increases simultaneously with the increase in speed of the compressor. When the boiler is under normal load, the steam pressure acting on a diaphragm 34, Fig. 2, opens the escape valve 35 of an oil-pressure control system to such an extent that the oil pressure in the system is sufficiently high to raise a spring- pressed piston 38 cutting out the control resistance 39 of a motor 21 rotating the cam-shaft 20 operating the mixture admission valves. When the steam pressure decreases upon an increase in the load, the valve 35 further restricts the escape of oil from the control system, and the oil pressure rises still further and opens successively valves 40-42 controlling the admission of boiler steam to the turbine 19. When the steam pressure rises upon a drop in load, the decreased oil pressure in the control system allows the piston to cut out the resistance 39 and to reduce the speed of the motor 21. If the speed of the compressor then falls below a certain point, a governor 31 on the compressor shaft so operates a valve 30 in another oil-pressure control system as to allow the oil pressure in that system to open a steam supply valve 33 of the turbine 19, which then brings the speed of the compressor up to the desired limit. The governor 31 may interrupt by a valve 43 the oil circulation in the control system of the steam valves 40-42 when the speed of the compressor rises to a certain maximum.