Patent GB-1242592-A (GB)
Title: Improvements relating to gas-turbine installations
IPC: F02C1/10
Filed: 1968-11-04
Abstract: 1,242,592. Gas turbine plant-closed cycle type. SIEMENS A.G. Nov.4, 1968 [Nov.2, 1967], No.52233/68. Heading F1G. A gas turbine plant comprises a first flow path for the working fluid which passes from the discharge side of the compressor through a first heat exchanger in which it is heated by working fluid discharging from the turbine, then to a second heat exchanger in which the working fluid is further heated by heat from a heat source, the heated working fluid then passing to the turbine. A by-pass flow path is provided whereby a portion of the working fluid discharged from the compressor will by-pass at least part of the first heat exchanger and will instead pass to a third heat exchanger where heat from the heat source at a lower temperature than at the second heat exchanger will be transferred to the by-pass working fluid before it rejoins the first flow path before entering the second heat exchanger. In the plant indicated in Fig.1, working fluid which is CO 2  enters the compressor 6 at a pressure of 110 atmospheres and temperature 40 C. and discharges therefrom at 310 ata and temperature 71 C., the CO 2  passing to a first heat exchanger 3 which is heated by CO 2  discharging from the turbine 5. A fraction of the high pressure CO 2 , 77%, passes wholly through the heat exchanger and discharges therefrom at 305 ata and 362 C., the second fraction, 23%, passing only partly through the heat exchanger 3 and discharging therefrom at 309 ata and 140 C. to a third heat exchanger 21 in which it is heated by combustion gases and discharges therefrom at 305 ata and 362 C. and then rejoins the first fraction. The working fluid then passes to a second heat exchanger 23 in which it is heated by combustion gases and discharges therefrom at 300 ata and 500 C. and passes to turbine 5 which drives the compressor 6 also an electric generator 7. The CO 2  discharges from the turbine at 115 ata and 386 C., passes through the heat exchanger 3 from which it discharges at 111 ata and 85 C. finally passing through a cooler 4 where it is cooled by water before passing back to the compressor 6 at 110 ata and 40 C. The combustion gases for the heat exchangers 23, 21 are generated in a combustion chamber 1 from which they discharge to the second heat exchanger 23 at 1100 C., the gases passing at lower temperature to the third heat exchanger 21 from which they discharge to atmosphere at 180 C. The heat exchanger 3 and the cooler 4 are shown in a combined unit in Fig.4. The units are mounted within a reinforced concrete structure 50, the working fluid discharging from the turbine 5 entering the structure through the closure member 51 and flowing downwardly over the coil 55 through which HP CO 2  from the compressor 6 is flowing. The LP CO 2  then flows upwardly through the space between the shells 56, 57 then downwardly through the space between the shell 57 and the outer casing, the CO 2  being cooled by water flowing through the coil 54. The cooled CO 2  at 110 ata and 40 C. then passes to the compressor 6. The paths indicating flow of HP CO 2  to the heat exchangers 21, 23 are also shown.