Method for operation of a gas turbine group

• US 20060248896A1
• Filed: 05/28/2004
• Published: 11/09/2006
• Est. Priority Date: 05/30/2003
• Status: Active Grant

• Current Assignee: Phoenix Biopower AB
• Original Assignee: Euroturine AB
• Inventors: Hansson, Hans-Erik
• Granted Patent: US 7,721,552 B2
• Time in Patent Office: Days
• US Class Current: 60/774
• CPC Class Codes: F01K 21/047 having at least one combustion gas turbine
• CPC Class Codes: F02C 3/305 Increasing the power, speed, torque or efficiency of a gas turbine or the thrust of a turbojet engine by injecting or adding water, steam or other fluids F01K21/04 takes precedence
• CPC Class Codes: F02C 6/18 using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10
• CPC Class Codes: F02C 7/08 Heating air supply before combustion, e.g. by exhaust gases
• CPC Class Codes: F02C 7/143 before or between the compressor stages
• CPC Class Codes: F05D 2260/2322 steam
• CPC Class Codes: F23L 7/005 Evaporated water; Steam
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]

Abstract

A method of operating a gas turbine power plant comprising of a first gas turbine group, consisting of a compressor and a turbine which are connected mechanically with one another, and a second gas turbine group, including a combustion device, which is placed in the gas flow stream between the first group'"'"'s compressor and turbine, whereby the second gas turbine group consists of a compressor, a fuel injection device, a combustion chamber and a turbine, whereby the second gas turbine group'"'"'s compressor and turbine are mechanically coupled to one another and at least one of the gas turbine groups having a device for the extraction of work, whereby the fact that a first flow of water and/or steam is heated with heat from the flue gas from the first group'"'"'s turbine, that further amounts of water and/or steam are heated with heat from a gas stream that is compressed by the first group'"'"'s compressor, and the produced water and/or steam is injected into the gas stream in such amounts that at least 60% of the oxygen content of the air in the stream is consumed through combustion in the combustion device, and in that the combustion gas that is fed into the turbine of the second gas turbine group has a pressure in the range 50-300 bar.

Claims

1. A method of operating a gas turbine power plant comprising of a first gas turbine group, consisting of a compressor e and a turbine which are connected mechanically with one another, and a second gas turbine group, including a combustion device, which is placed in the gas flow stream between the first group'"'"'s compressor and turbine, whereby the second gas turbine group consists of a compressor, a fuel injection device, a combustion chamber and a turbine, whereby the second gas turbine group'"'"'s compressor and turbines are mechanically coupled to one another and at least one of the gas turbine groups having a device for the extraction of useful work, characterised by the fact that a first flow of water and/or steam is heated with heat from the flue gas from the first group'"'"'s turbine, that further amounts of water and/or steam are heated with heat from a gas stream that is compressed by the first group'"'"'s compressor, and the produced water and/or steam is injected into the gas stream in such amounts that at least 60% of the oxygen content of the air in the stream is consumed through combustion in the combustion devices, and in that the combustion gas that is fed into the turbine of the second gas turbine group has a pressure in the range 50-300 bar.

2. A method according to claim 1, wherein that said further amount of water is introduced to the gas stream between the first group'"'"'s compressor and the second gas turbine group'"'"'s compressor.

3. A method according to claim 2, wherein that further amounts of water that entirely or partially has the form of steam optionally is introduced in the gas stream downstream of the second gas turbine group'"'"'s compressor, and in such amounts that at least 60% of the oxygen content of the air in the stream is consumed through combustion in the combustion device.

4. A method according to claim 1, wherein by a choice of operational characteristics such that the temperature of the gas flow entering the first gas turbine group'"'"'s turbine is at most 1200°

C., preferably 400-1000°

C., and that the pressure is between 5-60 bar.

5. A method according to claim 1, wherein by a choice of operational characteristics that give a flue gas exit temperature from the first gas turbine group'"'"'s turbine in the region of 200-500°

C.

6. A method according to claim 1, wherein by the fact that the first gas turbine group is a gas turbine unit, which is optimised for non-humidified operation, whereby the gas turbine unit can have multiple shafts and possibly include intercooling

7. A method according to claim 1, wherein by the fact that the second gas turbine group'"'"'s turbine is arranged and operated so that the pressure of the gas stream from the first gas turbine group'"'"'s compressor and to the first gas turbine group'"'"'s turbine, respectively, is re-allotted such that the first group is well-suited to operate with the media and flow data associated with humidified cycles.

8. A method according to claim 6, wherein by the regulation of the inlet guide vanes of the compressor of the first gas turbine group to reduce the flow of air obtained during operation of the power plant, and that the capacity of the first gas turbine group'"'"'s compressor may even be reduced through removing one or more compressor stages.

9. A method according to claim 1, wherein by the fact that the first gas turbine group'"'"'s compressor is complemented with an extraction device used to extract the compressed air, which is sealed against the axle, and the first gas turbine group'"'"'s turbine is complemented with an injection device, which is also sealed against the axle, to return the flue gas to the first gas turbine group'"'"'s turbine.

10. A method according to claim 1, wherein by the fact that the exit temperature from the first gas turbine group'"'"'s compressor is chosen to enable the production of steam of sufficiently high pressure to be used to cool the second gas turbine group'"'"'s turbine e and/or combustion chamber.

11. A method according to claim 1, wherein by combustion gases, which enter the second gas turbine group'"'"'s turbine, that have a pressure in the region of 50-300 bar, preferably 60-200 bar, or most desirably 80-150 bar, and a temperature in the region of 1000-2000 K, preferably 1200-1800 K.

12. A method according to claim 1, wherein by humidifying the gas exit flow from the second gas turbine group'"'"'s compressor prior to the second gas turbine group'"'"'s combustion device, preferably by passing at least a part of the said gas flow through a humidifier, whose inlet and outlet gas streams are preferably heat exchanged via a recuperator, where the inlet water to the humidifier are preferably heated with heat from the gas outlet stream from the first gas turbine group'"'"'s compressor and/or turbine.

13. A method according to claim 1, wherein by using at least a part of the water content of the flue gases to provide the process with feed water and/or steam.

14. A method according to claim 1, wherein by regulating the output of work from the process through changing the amount of water that is transferred to the gas stream, whereby a lower power output is obtained through a lower degree of humidification.

15. A method according to claim 1, wherein by the fact that at least a part of the steam used for cooling is introduced thereafter to the gas stream, preferably in the second gas turbine group'"'"'s combustion chamber, for further use as the working fluid.

16. A method according to claim 1, wherein by the fact that no significant amount of heat is transferred to the gas stream between the second gas turbine group'"'"'s turbine and the first group'"'"'s turbine.

17. A method according to claim 1, wherein by the fact that the second gas turbine group'"'"'s compressor is regulated by regulating the lead guide vane or by regulating the axle'"'"'s rotational speed.

18. A method according to claim 1, wherein by the fact that at least 10% of the useful work obtained from the process is extracted via the second gas turbine group'"'"'s transmission.

19. A method according to claim 1, wherein by the fact that a heat exchanger through which water flows, is arranged in the hot air flow downstream of the compressor of the first gas turbine group, for heating of the water, which optionally is preheated in an exhaust gas heat exchanger upstream of a flue gas condenser (from which the exhaust gas is exhausted from the gas turbine group to the environment, in that the water preferably is produced by the flue gas condenser (and in that a part flow of said water, preferably in preheated condition, is heated by a heat exchanger, which is passed by flue gas from the turbine of the first gas turbine group, and in that the water which is heated by the heat exchangers and which is possibly at least partially is transformed into steam, is fed into the combustion chamber, the turbine of the second gas turbine group or the compressed gas flow from the compressor of the second gas turbine group, for cooling of the turbine of the second gas turbine group.

20. A method according to claim 19, wherein that the water, which is fed into the combustion chamber, at least partially has the form of steam.

21. A method according to claim 19 wherein by producing steam by an external boiler and feeding the produced steam into the combustion chamber, the turbine of the second gas turbine group or the compressed gas flow from the compressor of the second gas turbine group, for cooling of the turbine of the second gas turbine group.