GB772287A - Power system incorporating a gas turbine - Google Patents

Abstract

772,287. Gas turbine plant. POWER JETS (RESEARCH & DEVELOPMENT), Ltd. Sept. 21, 1954 [Oct. 1, 1953; July 13, 1954], Nos. 26934/53 and 20502/54. Class 110 (3). A power system comprises an air storage reservoir for supplying air to a gas turbine, a source of heat for heating the air on its way from the reservoir to the turbine, a charging compressor for supplying air to the reservoir, energy supply connections from the turbine to means absorbing the useful power of the system and to the charging compressor and means for varying the turbine energy supplied to the charging compressor. The gas turbine 1, Fig. 1, drives an electric generator 2 supplying a network 3 through switchgear 4. A compressor 5 driven by the turbine 1 through a releasable coupling 14 and a variable gear-box 15 supplies air through piping 6 and non-return valve 7 and thence either by branch 6a and valve 8 into the reservoir 9 or by branch 6b to the turbine 1. A vent valve 19 is provided in the pipe 6. The air passing through the branch 6a is heated first in an exhaust heat-exchanger 10 and then in a heat-exchanger 12. The heatexchanger 12 receives its heat from an industrial plant or atomic pile 11. The power of the turbine 1 is equal to that of the compressor 5. When the load is low the switch 4 is opened and the coupling 14 engaged. The useful power of the plant is then used to compress air which is supplied to the reservoir 9. When the load increases, the output of the compressor 5 is reduced by means of the adjustable blades 5a or gear-box 15 so that less air is supplied to the reservoir 9. On further increase of load, the clutch 14 is disengaged and the vent valve 19 opened and the turbine 1 is supplied with air from the reservoir 9 only. A pump 23 is provided to vary the reservoir pressure by varying the head of water in the reservoir. There may be one compressor for supplying the air to the reservoir and another supplying the heater and turbine. The coupling 14 may be an electric or hydraulic coupling. In another arrangement, Fig. 2, the turbine 1 drives a generator 2 connected to the electrical network 3 through switch 4. The compressor 5 is driven by a variable speed electric motor 18 energized through switch 16. The switch 16 can be closed when switch 4 is opened so that the compressor 5 is driven by the turbine 1 when it is supplying no external load or the motor 18 can be driven at slow speed when the external load on the turbine 1 is below full load. A further compressor motor 33 may be connected direct to the network 3 as shown by the motor 33 driving the compressor 25. The motor 33 is supplied through a variable frequency changer 35. The compressor 25 supplies air through a pipe 26 and non-return valve 27 either to a reservoir 9a or a combustion chamber 30 supplying working fluid to a turbine 21. The turbine 21 drives a generator 22 connected to the network through a switch 24. The combustion chamber 30 may burn solid, liquid or gaseous fuel. Switches 24, 34 may be closed at the same time so that the generator supplies the network 3 which supplies the motor 33, but the switch 24 may be open while switch 34 and valve 41 is closed so that the power for driving the compressor 25 is taken from the network. Normal steam power plant may also be connected to the network. The number of compressors need not equal the number of turbines in the plant. The number of compressors running can be regulated in accordance with the load on the system. The reservoirs 9, 9a may be part of a common system. To carry overloads, a turbine 37 supplied direct from the reservoirs 9, 9a may be provided. The exhaust of the turbine 1 may pass through a waste-heat recovery system 36. In an emergency, if the reservoirs are exhausted, a part load can be carried by closing valve 8 or 28 and running turbine 1 or 21 on air delivered by its own compressor 5 or 25. When the plant is used intermittently for the supply of power, automatic means may be provided to keep up the store of air.