JPH0596759U - Gas turbine combustor - Google Patents

Abstract

(57) [Summary] [Structure] Cylindrical liner 3 placed inside outer cylinder 2.
The center body 4 is arranged inside the one end side in the axial direction. Air flowing from the air passage 5 between the outer cylinder 2 and the liner 3 into the premix chamber 6 between the axial direction one end side of the liner 3 and the center body 4 through the swirler 30, and the axis of the premix chamber 6 The fuel injected at one end in the direction is mixed.
The mixture is supplied to the combustion chamber 7 inside the liner 3 on the other end side in the axial direction. Liquid fuel and gaseous fuel are injected from the central portion of the other axial end of the center body 4 and one axial end of the premix chamber 6. [Effect] NOx can be reduced by the compact structure,
The turbine can be operated with both liquid and gaseous fuels.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas turbine combustor that can be operated by both liquid fuel and gas fuel.

[0002]

[Prior Art]

 A conventional gas turbine combustor is disclosed in JP-A-63-143423. This gas turbine includes an outer cylinder, a cylindrical liner arranged inside the outer cylinder, and a center body arranged inside one axial end of the liner. Between them is an air passage, the inside of the liner is a combustion chamber, and the fuel injection port and the auxiliary air supply port are provided at the axial end of the center body, and the fuel and air are mixed in the combustion chamber. It burns.

[0003]

[Problems to be solved by the device]

 In recent years, emission regulations of nitrogen oxides (NOx) have become strict, and it is required to reduce NOx in exhaust gas even in a gas turbine. However, the above-described conventional combustor structure cannot sufficiently reduce NOx.

Further, although both liquid fuel and gas fuel are used as fuel for the gas turbine, since a large fuel tank is required when liquid fuel is used regularly, gas supplied from a gas supply company is normally used. Fuel is used. However, there is a demand for a gas turbine that can be operated with both liquid fuel and gas fuel in order to ensure operation of the turbine when gas fuel is no longer supplied due to an accident.

An object of the present invention is to provide a combustor of a gas turbine that can solve the above technical problems.

[0006]

A feature of the present invention is that an outer cylinder, a cylindrical liner arranged inside the outer cylinder, and an inside of one end of the liner in the axial direction are arranged. A center body is provided, and an air passage is provided between the outer cylinder and the liner, a premix chamber is provided between one end of the liner in the axial direction and the center body, and the other end of the liner in the axial direction is provided. The inner part is the combustion chamber, and liquid fuel and gaseous fuel can be injected from the center part of the other axial end of the center body and one axial end of the premix chamber. A swirler is provided between the air passage and the premixing chamber so that the fuel injected at one end side and the air flowing in from the air passage can be mixed in the premixing chamber, and the air and the fuel are mixed. It is at the point where the air is supplied to the combustion chamber. It is preferable that the premixing chamber is provided with a throttle member for air-fuel mixture.

[0007]

[Action]

 According to the configuration of the present invention, NOx can be reduced by reducing the fuel concentration in the mixture of fuel and air. That is, at the time of startup, the fuel injected from the fuel injection port on the other axial end of the center body into the combustion chamber is burned, and the flame is retained in the combustion chamber. Then, the air supplied to the premixing chamber through the swirler from the air passage between the outer cylinder and the liner is mixed with the fuel injected from the fuel injection port on the one end side in the axial direction of the premixing chamber. The air-fuel mixture flows from the one end side in the axial direction to the other end side in the axial direction, is supplied to the combustion chamber, and is ignited by the flame held in the combustion chamber. That is, since the fuel and air can be sufficiently mixed in the premixing chamber and the flame held in the combustion chamber can reliably ignite, the fuel concentration of the mixture can be lowered to reduce NOx. ..

Further, since the liquid fuel injection port and the gas fuel injection port are provided at the center portion on the other end side in the axial direction of the center body and on the one end side in the axial direction of the premixing chamber, both the liquid fuel and the gas fuel are provided. Can also operate the turbine.

Further, by providing the air-fuel mixture throttle member in the pre-mixing chamber, the flow velocity of the air-fuel mixture flowing from the pre-mixing chamber into the combustion chamber can be surely made higher than the flame propagation speed. This prevents the flame in the combustion chamber from flowing back into the premixing chamber, so that it is possible to prevent the constituent members of the fuel injection port from being melted and damaged, and to promote the mixing of fuel and air in the premixing chamber.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

A gas turbine combustor 1 shown in FIG. 1 includes an outer cylinder 2, a cylindrical liner 3 arranged inside the outer cylinder 2, and one end side of the liner 3 in the axial direction (upper side in the drawing). ), And a center body 4 disposed inside. An air passage 5 is provided between the outer cylinder 2 and the liner 3, and the other axial end of the air passage 5 is connected to an unillustrated compressed air supply source. The other end of the liner 3 in the axial direction is attached to the scroll of the turbine main body not shown in the drawing, and a plurality of air introduction holes 3a are formed in the outer wall. Can be introduced into the liner 3. A premixing chamber 6 is formed between one end of the liner 3 in the axial direction and the center body 4, and a combustion chamber 7 is formed inside the other end of the liner 3 in the axial direction. Is guided to the turbine blade (not shown) through the scroll. A spark plug 18 is attached to the liner 3.

Liquid fuel and gaseous fuel can be injected into the combustion chamber 7 from the center of the other axial end of the center body 4. That is, the center body 4 includes an inner layer member 4a, a cylindrical intermediate layer member 4b that is removably fitted to the inner layer member 4a, and a tube that is removably fitted to the intermediate layer member 4b. The outer layer member 4c has a main shape and is detachably attached to the outer cylinder 2 through bolts (not shown). A liquid fuel supply hole 10 is formed along the axis of the inner layer member 4a, one end of the liquid fuel supply hole 10 in the axial direction is connected to a liquid fuel supply source (not shown), and the other end in the axial direction is a liquid fuel injection port. It is supposed to be 9. A gas fuel supply passage 12 is provided between the inner layer member 4a and the intermediate layer member 4b, one end of the passage 12 in the axial direction is connected to the gas fuel supply source, and the other end in the axial direction is the gas fuel injection port 11 It is said that.

Liquid fuel and gaseous fuel can also be injected into one end of the premix chamber 6 in the axial direction. That is, the liquid fuel manifold 15 is attached to the outside of the one end of the outer cylinder 2 in the axial direction. The liquid fuel manifold 15 includes a ring portion 15b connected to a liquid fuel supply source (not shown) via a pipe 15a, a plurality of branch pipes 15c radially inwardly projecting from the ring portion 15b, and the branch pipe 15c. And a liquid fuel injection tip 15d provided at the tip of the. Each tip 15c is fitted to an annular block 16 which is detachably attached to the outer cylinder 2 by a bolt (not shown), and liquid fuel is injected from the fuel injection port 15e at the tip thereof to one axial end of the premix chamber 6. To do. Further, a gas fuel supply manifold 20 is provided so as to surround the liquid fuel supply manifold 15. The gas fuel supply manifold 20 includes a ring portion 20b connected to a gas fuel supply source (not shown) via a pipe 20a, and a plurality of branch pipes 20c protruding radially inward from the ring portion 20b. The tip of each branch pipe 20c is connected to an annular block 21 that is detachably attached to the outer cylinder 2 by bolts (not shown), and premixed via a gas fuel passage 22 formed in the block 21 and the outer cylinder 2. Gaseous fuel is injected into one end of the chamber 6 in the axial direction. In the present embodiment, each fuel injection port 23 at the tip of the gaseous fuel passage 22 and each liquid fuel injection port 15e are arranged on a circle concentric with each other.

Pre-mixing with the air passage 5 so that the fuel injected into one end of the pre-mixing chamber 6 in the axial direction and the air flowing from the air passage 5 can be mixed in the pre-mixing chamber 6. A swirler 30 is provided between the chamber 6 and the chamber 6. As shown in FIG. 2, the swirler 30 has a plurality of vanes 30a for swirling the air flowing into the premixing chamber 6 from the air passage 5, and a flange 3b formed at one axial end of the liner 3. It is configured by being provided between the outer cylinder 2 and the outer cylinder 2.

The air-fuel mixture mixed in the premixing chamber 6 flows through the premixing chamber 6 from one end side in the axial direction to the other end side as shown by an arrow in the figure, whereby the combustion chamber 7 is supplied. An annular member 40 that throttles the air-fuel mixture in the premix chamber 6 is welded to the inner peripheral surface of the liner 3. As a result, the flow velocity of the air-fuel mixture flowing from the premixing chamber 6 into the combustion chamber 7 is increased, and is higher than the flame propagation speed in the combustion chamber 7.

Gas fuel is usually supplied to the combustor 1, and the gas fuel injected from the gas fuel injection port 11 of the center body 4 into the combustion chamber 7 is ignited by the plug 18 when the turbine is started. Is ignited and the flame is retained in the combustion chamber 7. Then, the gaseous fuel injected from the gaseous fuel injection port 23 to one end side in the axial direction of the premixing chamber 6 and the air-fuel mixture which flows from the air passage 5 into the premixing chamber 6 through the swirler 30. , Is accelerated by the throttle member 40 and flows into the combustion chamber 7. This mixture is ignited and burned by the flame held in the combustion chamber 6, and the combustion gas is supplied to the turbine blades.

When the gaseous fuel cannot be supplied for any reason, the liquid fuel is injected from the liquid fuel injection ports 9 and 15e, and the same combustion as in the case of the gaseous fuel is performed.

According to the above configuration, the fuel and the air can be sufficiently mixed in the premix chamber 6, and the mixture held by the flame held in the combustion chamber 7 can be reliably ignited. NOx can be reduced by lowering the fuel concentration. Further, the turbine can be operated with both liquid fuel and gaseous fuel. Further, since the flow velocity of the air-fuel mixture flowing from the premix chamber 6 into the combustion chamber 7 can be surely made higher than the propagation velocity of the flame, it is possible to reliably prevent the backflow of the flame from the combustion chamber 7 to the premix chamber 6, It is possible to prevent the constituent members of the fuel injection ports 9, 11, 15e, and 23 from being melted, and to promote the mixing of air and fuel in the premix chamber 6. Further, the constituent members of the liquid fuel injection ports 9 and 15e and the gas fuel injection ports 11 and 23 can be easily attached and detached, and the maintenance thereof is easy.

[0019]

According to the combustor of the gas turbine of the present invention, NOx can be reduced with a compact structure, and the turbine can be operated with both liquid fuel and gas fuel. Furthermore, by providing a mixture restricting member in the premixing chamber, it is possible to prevent the flame from flowing back from the combustion chamber to the premixing chamber, and to promote the mixing of fuel and air.

[Brief description of drawings]

FIG. 1 is a sectional view of a combustor of a gas turbine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

[Explanation of symbols]

 2 Outer cylinder 3 Liner 4 Center body 6 Premixing chamber 7 Combustion chamber 30 Swirler 40 Throttling member

Claims (2)

[Scope of utility model registration request] 1. An outer cylinder, a tubular liner arranged inside the outer cylinder, and a center body arranged inside one end side of the liner in the axial direction. Between them is an air passage, the pre-mixing chamber is between the one axial end of the liner and the center body, and the inside of the other axial end of the liner is the combustion chamber. Liquid fuel and gaseous fuel can be injected from the end-side central portion and one end side in the axial direction of the premixing chamber, and the fuel injected to the one end side in the axial direction of the premixing chamber and the air flowing in from the air passage are separated. A swirler is provided between the air passage and the premixing chamber so that the air can be mixed in the premixing chamber, and the mixture of the air and the fuel is supplied to the combustion chamber. Combustor. 2. The combustor for a gas turbine according to claim 1, wherein the premixing chamber is provided with a throttle member for air-fuel mixture.