GB707480A - Improvements in and relating to gas turbine plants - Google Patents

Abstract

707,480. Gas turbine plant. PARSONS & CO., Ltd., C. A. Dec. 13, 1951, No. 29222/51. Class 110(3) In a gas turbine plant comprising a compressor driven by a turbine which exhausts to an independent power turbine the exhaust gases of which pass through a combustion chamber and a h.eat exchanger. heating the air between the compressor. and the compressor turbine, to a steam generator, controllable quantities of hot air are tapped from the exhaust of the power turbine or any point in the circuit between the compressor and the power turbine exhaust and mixed with the air entering the compressor, and further controllable quantities of air are tapped from a stage of the compressor or between the compressor turbine and power turbine or both and led direct to the combustion chamber. The plant shown comprises a two stage compressor 3, 4 which discharges through a heat exchanger 11 to a compressor turbine 6 which exhausts through a chamber 7 to a power turbine 8a. The exhaust gases from the power turbine pass through a duct 8b to a combustion chamber 9 which heats the air between the compressor 3, 4 and the compressor-turbine 6. The gases leaving the heat exchanger 11 pass through a steam generator 13 to the exhaust duct 15. A duct 14 is provided to enable the exhaust gases to by-pass the steam generator. Valves 16, 17 in the ducts 14. 15 are controlled by a pressure regulator 18 so that the valve 16 is opened and valve 17 closed, when a predetermined steam pressure is reached. If it is desired to increase the steam supply from the steam generator 13. the valves 37, 38 are opened and hot air passed to the intake of the compressor 3, 4. This results in an increase in the temperatures of the exhaust gases of the turbine 8a and so increases the output of the steam generator. If a further increase is desired, the valves 43 and 45 may be opened. The air passing through these valves passes through injectors which increase the flow through the duct 36. The inlet throttle 2 may also be used to increase the flow through the duct 36. A still further increase in output of the steam generator 13 may be obtained by opening valves 33, 35 so passing air direct to the combustion chamber 9 in which more fuel may then be burnt. Hot air may also be led to filters 40 through which air enters the compartment 41 containing the plant. The steam from the generator 13 may be used to operate auxiliaries of the plant through pipes 21 or added to the air leaving the compressor through a pipe 48. Steam is also used to operate a turbine 22 which drives an electric generator 23 which may be used as a motor. The electric generator 23 is connected to the turbine 22 and a blower 24 by clutches 25. In starting, the generator 23 is energized from the battery 27 to drive the blower 24. Air then passes through the compressor 34, heat exchanger 11, turbines 6, 8a to the combustion chamber 9 and steam generator 13. The valves 33 and 35 may be opened to increase the air flow to the combustion chamber 9. When the compressor is up to speed, the throttle 2 may be opened and the blower shut down. In a modification, the compressor is run up to speed by an electric motor fed with current by an auxiliary Diesel set. After starting, the valves 37. 43 and 45 may be opened to control the speed of the compressor.