Patent GB-416463-A (GB)
Title: Improvements in constant pressure gas turbine plant
IPC: F02C3/36
Filed: 1934-03-07
Abstract: 416,463. Gas turbine plants. TENNANT, W. J., 111, Hatton Garden, London.-(Aktiebolaget Milo ; 32, Kungsgatan, Stockholm.) March 7, 1934, No. 7315. [Class 110 (iii).] A constant pressure gas turbine plant comprises a turbine driving a shaft doing external work, a turbine on a separate shaft driving a compressor which supplies air to the combustion chamber, a governor on the former shaft which regulates the supply of fuel to the combustion chamber in accordance with the external load, and an additional governor which controls the outlet temperature of the exhaust gases from the turbine system. The additional governing device may be controlled by the inlet or outlet temperatures of the gases, by the gas pressure, before or after a turbine, or electrically, or by the speed of a turbine shaft. In Fig. 2 the combustion chamber 7 supplies a turbine 1 driving a generator 2, and a turbine 3 driving a compressor 4 which supplies air to the chamber 7 after being heated in an exchanger 6 through which the exhaust gases flow. A governor L controls the fuel supply to the chamber 7. A thermostat 24 may be provided in one or both turbine exhausts to control the valve 11 leading to the turbine 1. In the event of a high exhaust temperature being reached this causes turbine 3 to consume a larger amount of fuel, supply more air from the compressor and thus reduce the temperatures of the exhaust gases. A second governor 25 controls valve 11 in accordance with the speed of turbine 3. A second combustion chamber may be provided before turbine 3, the fuel valve being controlled by the thermostat 24. In another form the additional governor may be a piston under pressure of gas in the conduit 10, so that if the pressure drops, valve 11 is throttled and more gas is supplied to turbine 3. In Fig. 5 the turbine 3 is of the double-rotation radial flow type driving high and low pressure compressors 41, 4<11>. In a further arrangement, the two turbines are in series, the L.P. turbine driving the compressor. A byepass in the supply pipe places the turbines partly in parallel. Some of the exhaust gases from turbine 1 pass to an intermediate stage in turbine 3. The valves in the exhaust and byepass lines are controlled electrically in accordance with the load on the generator 2. In another plant an intermediate pressure turbine drives a generator, and H.P. and L.P. turbines drive compressors supplying a combustion chamber, water being sprayed into the air for cooling purposes. The turbines are in series, but byepassing arrangements are provided. The additional control in a plant may vary the gas mixture strength by admitting air into the working fluid. In a further arrangement in which the H.P. turbine drives the compressor and the L.P. turbine a generator, four valves leading to the second turbine are controlled in series by a thermostat placed in the exhaust pipe from the H.P. turbine. The exhaust temperatures may be controlled by injection of water, it may be into the combustion chamber. Fig. 16 shows a double-rotation turbine 1 driving two generators 2, 2<1>, and a H.P. air compressor 4<11>. A L.P. turbine drives compressors which deliver air to the compressor 4<11>. Fuel from a tank 48 is delivered by a pump 49 through a valve 9 controlled by governor L, partly to a chamber 7 to feed the turbine 1, and partly through a valve 51, controlled by a thermostat 24, to an intermediate heating chamber 46. A final layout shows how a fuel valve leading to the combustion chamber is controlled by a thermostat and a pressure device both attached to the exhaust gas pipe.