Gas turbine and gas-turbine plant having the same

Patent metadata

Field	Value
Publication number	US-9347377-B2
Application number	US-201113806961-A
Country	US
Kind code	B2
Filing date	Oct 27, 2011
Priority date	Oct 28, 2010
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

The invention provides a gas-turbine fuel nozzle that includes a plurality of fuel supply channels to which fuel is supplied, a plurality of fuel/sweep-fluid supply channels to which fuel or a sweep fluid for sweeping the fuel is supplied, and a plurality of injection holes that are provided at downstream ends of the fuel supply channels or the fuel/sweep-fluid supply channels and that inject the fuel guided from the fuel supply channels or the fuel/sweep-fluid supply channels; a sweep-fluid supply channel that is connected to the fuel/sweep-fluid supply channels to guide the sweeping; and sweep-fluid cooling means for cooling the sweep-fluid to a temperature lower than a self-ignition temperature of the fuel.

First claim

The invention claimed is:

1. A gas turbine comprising:
a gas-turbine fuel nozzle that includes a plurality of fuel supply channels to which fuel gas is supplied, a plurality of fuel/sweep-fluid supply channels which are separated from the fuel supply channels and to which one of fuel gas and a sweep fluid for sweeping the fuel gas is selectively and switchably supplied, and a plurality of injection holes that are provided at downstream ends of the fuel supply channels and the fuel/sweep-fluid supply channels and that inject the fuel gas or the sweep fluid guided from the fuel supply channels or the fuel/sweep-fluid supply channels; and
a sweep-fluid supply channel that is connected to the fuel/sweep-fluid supply channels and guides the sweep fluid;
wherein the gas turbine is configured to continuously supply the sweep fluid to the fuel/sweep-fluid supply channels while the fuel gas is not supplied to the fuel/sweep-fluid supply channels,
the gas turbine further comprising sweep-fluid cooling means for cooling the sweep fluid to a temperature lower than a self-ignition temperature of the fuel gas.

2. The gas turbine according to claim 1 ,
wherein the sweep-fluid supply channel is for connecting the fuel/sweep-fluid supply channels and a casing of the gas turbine, and configured to guide, as the sweep fluid, air in the casing to the fuel/sweep-fluid supply channels; and
the sweep-fluid cooling means is a plurality of projections that are provided around the sweep-fluid supply channel.

3. The gas turbine according to claim 2 , wherein the plurality of projections are provided adjacent to suction ports for ventilation fans provided on a gas-turbine outer case that encloses the gas turbine.

4. The gas turbine according to claim 1 ,
wherein the sweep-fluid supply channel is connected to the fuel/sweep-fluid supply channels and to a casing of the gas turbine and guides, as the sweep fluid, a fluid extracted from the casing; and
the sweep-fluid cooling means is heat-exchange means that is provided in the sweep-fluid supply channel and that performs heat exchange between a cooling medium and the sweep fluid.

5. The gas turbine according to claim 4 ,
wherein the heat-exchange means is a gas-turbine cooling-air cooler; and
the sweep fluid is part of the fluid cooled by the gas-turbine cooling-air cooler.

6. The gas turbine according to claim 4 , wherein the heat-exchange means is of a water cooling type that uses water as the cooling medium.

7. A gas turbine according to claim 1 , wherein the sweep-fluid cooling means is a compressor that supplies compressed air at a temperature lower than a self-ignition temperature of the fuel gas to the sweep-fluid supply channel as the sweep-fluid.

8. The gas turbine according to claim 1 , further comprising a fuel-flow-rate control valve that is provided on a channel which is provided at an upstream side of the fuel/sweep-fluid supply channels and that controls the flow rate of the fuel gas, a fuel-pressure control valve that is provided on the channel and that controls the pressure of the fuel gas, atmospheric discharge pipe branching out from the pipe at a portion between the fuel-flow-rate control valve and the fuel-pressure control valve, and a vent valve provided on the atmospheric discharge pipe.

9. The gas turbine according to claim 1 ,
wherein the sweep-fluid supply channel comprises a sweep-fluid supply on-off valve on a downstream side of the sweep-fluid cooling means and a sweep-fluid discharge channel that extends from a portion between the sweep-fluid cooling means and the sweep-fluid supply on-off valve;
the sweep-fluid discharge channel comprises a sweep-fluid discharge on-off valve; and
when the gas turbine is started-up, the sweep-fluid supply on-off valve is completely closed, and the sweep-fluid discharge on-off valve is completely opened.

10. The gas turbine according to claim 9 ,
wherein the sweep-fluid supply on-off valves are provided with two on-off valves located at two positions on the downstream side relative to the sweep-fluid discharge channel,
wherein the gas turbine further comprises a sweep-fluid depressurizing channel branching off from a portion of the sweep-fluid supply channel at a position between the two sweep-fluid supply on-off valves,
wherein the sweep-fluid depressurizing channel comprises a sweep-fluid depressurizing on-off valve that is operated in conjunction with actuation of at least one of the two sweep-fluid supply on-off valves; and
wherein the sweep-fluid depressurizing on-off valve is completely opened when at least one of the two sweep-fluid supply on-off valves is completely closed.

11. The gas turbine according to claim 9 , further comprising:
a control device that has a load reduction function for reducing an operating load on the gas turbine and an emergency stop function for stopping the operation of the gas turbine,
wherein the control device is configured to receive a signal which indicates degrees-of-opening of the sweep-fluid supply on-off valve,
wherein the control device activates the emergency stop function and/or the load reduction function when the control device determines that the sweep-fluid supply on-off valves are in abnormal states based on the received signal indicating degrees-of-opening.

12. The gas turbine according to claim 10 , wherein an orifice is provided on a downstream side of the sweep-fluid discharge on-off valve or on a downstream side of the sweep-fluid depressurizing on-off valve.

13. The gas turbine according to claim 1 , further comprising:
a temperature sensor that is provided on the downstream side of the sweep-fluid cooling means and detects the temperature of the sweep fluid taken out from the sweep-fluid cooling means; and
a control device that has a load reduction function for reducing the operating load on the gas turbine,
wherein the control device operates the load reduction function when the control device determines that the temperature of the sweep fluid detected by the temperature sensor is equal to or higher than a self-ignition temperature of the fuel gas.

14. The gas turbine according to claim 13 , wherein, at a period of load rejection, the control device stops the supply of the sweep fluid and increases the flow rate of the fuel gas that is combusted by a premix method and that is supplied to the fuel supply channels.

15. The gas turbine according to claim 1 , wherein the gas-turbine fuel nozzle is a pilot nozzle to which the fuel gas is guided, the fuel gas that is combusted by a diffusion method is supplied to the fuel/sweep-fluid supply channels, and the fuel gas that is combusted by a premix method is supplied to the fuel supply channels.

16. The gas turbine according to claim 1 , wherein the gas-turbine fuel nozzle is a dual-fuel firing pilot nozzle to which the fuel gas or liquid fuel is guided, the fuel gas that is combusted by a diffusion method is supplied to the fuel/sweep-fluid supply channels, and the liquid fuel that is combusted by the diffusion method is supplied to the fuel supply channels.

17. The gas turbine according to claim 1 ,
wherein the gas-turbine fuel nozzle is a main nozzle in which the fuel gas that is combusted by a premix method is supplied to the fuel/sweep-fluid supply channels, or the sweep fluid is supplied to the fuel/sweep-fluid supply channels; and
a plurality of the main nozzles are provided, and the sweep fluid is supplied to some of the main nozzles according to the operation of the gas turbine.

18. A gas-turbine plant comprising a gas turbine according

Assignees

• Murakami Masayuki
• Higashi Kazuya
• Nakamoto Yukimasa
• Fujii Satoko
• Shimizu Takeyuki
• Matsumoto Keigo
• Mitsubishi Hitachi Power Sys

Inventors

• Murakami Masayuki
• Higashi Kazuya
• Nakamoto Yukimasa
• Fujii Satoko
• Shimizu Takeyuki
• Matsumoto Keigo

Classifications

• F23R3/343

  Pilot flames, i.e. fuel nozzles or injectors using only a very small proportion of the total fuel to insure continuous combustion (ignition in gas-turbine plants F02C7/264; pilot flame igniters F23Q9/00) · CPC title

• F23R3/36

  Supply of different fuels · CPC title

• F02C9/40

  specially adapted to the use of a special fuel or a plurality of fuels · CPC title

• F02C7/228

  Dividing fuel between various burners · CPC title

• F05D2260/608

  Aeration, ventilation, dehumidification or moisture removal of closed spaces · CPC title