Method for operating a gas turbo group

• US 20040216462A1
• Filed: 02/11/2004
• Published: 11/04/2004
• Est. Priority Date: 02/11/2003
• Status: Active Grant

• Current Assignee: Alstom Technology Ltd. (Alstom SA)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Hellat, Jaan, Tschirren, Stefan, Dittmann, Rolf
• Granted Patent: US 7,069,727 B2
• Time in Patent Office: Days
• US Class Current: 60/773
• CPC Class Codes: F02C 7/26 Starting; Ignition
• CPC Class Codes: F02C 9/28 Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed F02C9/30 - F02C9/38, F02C9/44 take precedence
• CPC Class Codes: F05D 2270/083 by monitoring combustion conditions
• CPC Class Codes: F05D 2270/304 Spool rotational speed
• CPC Class Codes: F23C 13/02 characterised by arrangements for starting the operation, e.g. for heating the catalytic material to operating temperature
• CPC Class Codes: F23C 13/06 in which non-catalytic combustion takes place in addition to catalytic combustion, e.g. downstream of a catalytic element
• CPC Class Codes: F23C 2900/13002 Catalytic combustion followed by a homogeneous combustion phase or stabilizing a homogeneous combustion phase
• CPC Class Codes: F23N 2241/20 Gas turbines
• CPC Class Codes: F23R 3/40 characterised by the use of catalytic means

Abstract

A gas turbo group has a combustion chamber comprising a catalytic burner stage (2), a preburner stage (1) located upstream from the catalytic burner stage, as well as a non-catalytic burner stage (11, 5, 6) located downstream from the catalytic burner stage. The preburner stage serves to always maintain a temperature (T₁) at the inlet into the catalytic stage that corresponds at least to a minimum temperature (T_MIN) necessary for operating the catalytic burner stage. According to the invention, the gas turbo group is operated so that the burner stage located downstream from the catalytic combustion chamber is taken into operation only when the temperature (T₂) at the outlet from the catalytic stage has reached an upper limit in the presence of a maximum combustion air mass flow.

Claims

1. A method for operating a gas turbo group, which gas turbo group includes at least one combustion chamber, wherein the combustion chamber includes at least one catalytic first burner stage and a second, non-catalytic burner stage following the at least one catalytic burner stage in the flow direction, the method comprising:

determining a net power output (P_ACT) of the gas turbo group;

supplying the gas turbo group with a total fuel mass flow ({dot over (m)}_FUEL) of the gas turbo group depending on a control deviation (P_SET-P_ACT) of the net power output;

distributing the total fuel mass flow to at least the catalytic burner stage and the non-catalytic burner stage;

determining the temperature (T₂) at the outlet from the catalytic burner stage; and

regulating, limiting to a set value, limiting to a maximum value, or combinations thereof, the temperature at the outlet from the catalytic burner stage by changing the combustion air mass flow and blocking the fuel supply to the non-catalytic burner stage when the combustion air mass flow is below an achievable maximum.

2. A method according to claim 1, wherein changing the combustion air mass flow comprises adjusting an adjustable guide row of a compressor of the gas turbo group.

3. A method according to claim 2, comprising:

keeping the adjustable compressor guide row closed when the temperature at the outlet from the catalytic burner stage is below a set value.

4. A method according to claim 1, comprising:

cooling suction air upstream from the compressor in order to increase the combustion air mass flow.

5. A method according to claim 4, further comprising:

injecting liquid droplets into the suction air for cooling.

6. A method according to claim 1, further comprising:

operating a non-catalytic preburner stage upstream from the catalytic burner stage.

7. A method according to claim 6, further comprising:

determining the temperature (T₁) at the inlet into the catalytic stage; and

regulating compliance with a minimum value of the temperature at the inlet into the catalytic stage by adjusting the fuel mass flow {dot over (m)}_P to the preburner stage.

8. A method according to claim 6, comprising:

operating the preburner stage in a diffusion combustion mode.

9. A method according to claim 1, further comprising:

in the presence of a maximum combustion air mass flow, supplying a fuel mass flow ({dot over (m)}_SEV) additionally necessary for regulating the net power output to a combustion chamber or burner stage located downstream from the catalytic burner stage.

10. A method according to claim 1, further comprising:

operating the second non-catalytic burner stage as a self-igniting combustion chamber.

11. A method according to claim 1, wherein the regulating value of the temperature at the outlet from the catalytic stage corresponds essentially to the maximum permissible temperature of the catalyst material.

12. A method according to claim 1, wherein the regulating value of the temperature at the outlet from the catalytic stage is higher than the temperature necessary for a spontaneous self-ignition of the fuel in the second non-catalytic burner stage.

13. A method according to claim 9, wherein the presence of a maximum combustion air mass flow comprises a fully opened adjustable guide row.

14. A method according to claim 9, wherein a combustion chamber or burner stage comprises the non-catalytic burner stage.