GB478688A - Improvements in gas turbine plant - Google Patents

Abstract

478,688. Gas turbines. SOC. RATEAU, and ANXIONNAZ, R. Aug. 6, 1936, No. 21711. Convention date, Dec. 9, 1935. [Class 110 (iii)] In a gas-turbine plant, gas is compressed in compressors driven by auxiliary turbines separate from the main turbines, and the gases exhausting from one or more turbines pass through a heat exchanger to heat up gas being delivered by the compressors. The compressors may have inter-coolers fitted between each two stages of compression. Fig. 3 shows a number of auxiliary turbines ta<1> ... ta<4> driving compressors c<1> ... c<4> having intercoolers r<1> ... r<3>. The exhaust gases from auxiliary turbines, and main turbines tm<1> ... tm<4> pass to an interchanger e to heat compressed gases delivered to heating chambers having burners f<1>, f<2>. Re-heating burners g<1>, g<2> are supplied. The turbines may be arranged in a series such as tm<1>, ta<1>, tm<2>, ta<2> ... and so on. In Fig. 4, turbine rotors 2, 3 drive compressors c<1>, c<2> and turbine rotors 1, 4 are connected to external gearing 6 ... 8. In a modification, four turbine rotors on four separate shafts, may be fed with gas in series. All the rotors may be arranged in one casing. By fitting valves between each pair of compressors, and also between each pair of auxiliary turbines in series, the first auxiliary turbine may be started up to drive its compressor, then the second turbine and its compressor, and so on. Fig. 7 shows a plant in which thermostats u<1>, u<2> regulate the amount of fuel fed to the burners f<1>, f<2>. A governor 17 on the shaft of the turbine tm controls a valve 18 and thus the amount of air supplied to the burner f<2>. The difference in pressure on the two sides of the valve 18 actuate, through a manometric device 19, a valve 20 in the inlet pipe to the compressor c. The governor 17 may control the quantity of fuel fed to the burner f<2>, and the burner f<1> may be controlled by a thermostat in the combustion chamber leading to the auxiliary turbine. The governor 17 and a thermostat may act on opposite ends of a lever attached to the fuel burner valve f<2>. In another arrangement, an open furnace heater heats the exhaust gases from two auxiliary turbines, on their way to a heat exchanger through which passes the delivery pipe from the compressor. Part of the air only may pass through the furnace or combustion chamber, being rejoined after heating, by a stream which byepasses the furnace. The latter stream may pass through a jacket outside the combustion chamber. In Fig. 16 a chamber 31 is placed to the rear of the combustion chamber 28, to collect unburnt liquid fuel. A screen 32 shields the chamber 31 from the heat of combustion.