Patent GB-989018-A (GB)
Title: Improvements in or relating to thermal power plants
IPC: F02C1/00
Filed: 1962-04-24
Abstract: 989,018. Gas turbine plant. ESCHER WYSS A.G. April 24, 1962 [April 24, 1961 ], No. 15637/62. Heading F1G. A thermal power plant comprises a closed circuit for a gaseous working medium, the plant having a compressor by which the working medium is raised to high pressure and a heater by which the working medium is heated by heat exchange with the gases produced by combustion of fuel, the heated working medium being then expanded in a turbine which drives the compressor and in a separate power turbine. An open circuit gas turbine plant is also provided, the compressor of which is arranged to supply combustion air to the heater of the closed circuit, there being in addition to the turbine driving the compressor, a separate power turbine which is connected to the turbine and compressor assembly of the closed circuit. In Fig. 1, the closed circuit plant comprises a compressor 1, the working fluid of which, for example air, is heated in a heat exchanger 2 and then in a heat exchanger 3, the air then being expanded through a turbine 5 which drives the compressor 1. The air is then passed to a separate power turbine 6 which drives a ship's propeller 8 through gearing 7, the air then being passed through the heat exchanger 2 where it transfers heat to the air passing from the compressor 1, and finally through the cooler 9 before re-admission to the compressor 1. The open circuit plant comprises an air compressor 12, air from which is preheated in heat exchanger 15, the air then being passed to the combustion section of heat exchanger 3 where fuel is burned with the air, the combustion gases then passing through a further combustion section 16 and then passing into the turbine 13. The gases from the turbine 13 are then further expanded in the separate power turbine 14, which is connected by means of a clutch 17 to the turbine and compressor assembly 1, 5 of the closed circuit, and the gases finally pass through the heat exchanger 15 to preheat the air discharging from the compressor 12. The turbines 6 and 14 may be by-passed by opening the by-pass valves 21 and 23 respectively. A starter motor 11 is connected to the compressor and turbine assembly 1, 5 by gearing 10. An auxiliary compressor 26 is provided for supercharging the closed circuit. A line 31 connected to the outlet of the compressor 12 of the open circuit is also provided for this purpose. In a second embodiment, Fig. 2, two combustion type air heaters 3<SP>1</SP> and 3<SP>11</SP> are provided in place of the single unit 3 shown in Fig. 1. The air in the closed circuit is divided into two streams for heating in the heaters 3<SP>1</SP> and 3<SP>11</SP> and the streams re-join to enter the turbine 5. Air from the compressor 12 of the open circuit passes to the combustion section of the heater 3<SP>1</SP>, and the combustion gases are further heated in the combustion section 16 before entering the turbine 13. The gases discharging from the turbine 13 pass to the combustion section of the heater 3<SP>11</SP> and are reheated by combustion of further fuel, the gases then passing tothe separate power turbine 14. In a further embodiment, two combustion type heaters 3<SP>1</SP>, 3<SP>11</SP> are again provided, air from the compressor 12 passing to the combustion section of the heater 3<SP>1</SP>, the combustion gases therefrom passing to the separate power turbine 14, the gases from this turbine being re-heated in the combustion section of the heater 3<SP>11</SP> and further re-heated in the combustion section 16 before passing into the turbine 13 which drives the compressor 12.