JPH0356368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flame monitoring device for a gas turbine for monitoring whether or not a flame in a combustion chamber is blown out.

[Conventional technology]

For example, in an industrial gas turbine that employs a multi-can type in which multiple combustors are arranged circumferentially, even if one of the multiple combustors blows out, it is necessary to prevent it from blowing out for safety reasons. It is necessary to reliably detect this and take measures to cut off the combustion supply.

As one countermeasure, conventionally, a thermometer was installed at the turbine outlet of the gas turbine, and the thermometer was configured to measure the temperature of the combustion gas to monitor the blowout. Ta.

In these temperature monitoring devices,
Measuring the temperature peak value in the circumferential direction at the turbine outlet has been adopted as an effective method because the temperature drop during blowout becomes noticeable.
Until such temperature peak values are measured to monitor blowout, there are variations in both the outlet temperature distribution of the entire combustor, which is made up of multiple combustors, and the temperature distribution at the outlet of each combustor. Since the outlet section is a location affected by the rotation of the turbine, the temperature peak value described above decreases, and as a result, there is another level of uncertainty in determining blowout based on such a low temperature peak value.

In order to eliminate such uncertainties, for example, a monitoring device disclosed in Japanese Patent Publication No. 54-19946 has been proposed.

As shown in FIG. 2, a gas turbine equipped with this monitoring device has a plurality of combustors 1 arranged, and a pair of adjacent combustors 1, 1
The adjacent pair of combustors 1,
The ignition plugs 3 are provided by selecting a specific pair that is farthest from the ignition plugs 1, and the ignition system 4 is connected to these ignition plugs 3.

In this case, the flame propagates through the flame propagation tube 2 in the lower left and right directions in the figure due to the direct flame, so that the combustor 1 becomes sequentially in a combustion state. 1 and 1 are each equipped with a monitoring device.

[Problem to be solved by the invention]

This monitoring device inserts a peep tube 5 into the inner cylinder (not shown) of the combustor 1 at the terminal end from the radial direction,
The inner end of the peep tube 5 is set so as to face a flame generation location within a combustion chamber (not shown).

In such a monitoring device, it is necessary to attach a viewing tube 5, which is disadvantageous in terms of processing.In particular, since the inner tube is exposed to high temperatures, there are many difficulties in processing, which has been a problem.

Further, in the structure in which the peep tube 5 is inserted through the inner tube of the combustor 1, the position where the peep tube 5 is provided is limited in terms of space due to the relationship with surrounding members. In contrast, the flame is generated within a very limited range in the longitudinal direction of the combustor 1. Therefore, if the position of the peep tube 5 deviates even slightly in the longitudinal direction of the combustor 1 from the optimum range limited for flame monitoring, a technical problem arises in that the peep tube 5 becomes difficult to detect the flame.

By the way, conventionally, an air injection nozzle is inserted coaxially into the fuel injection nozzle of a gas burner, and a configuration is disclosed in which the flame inside the combustion chamber is monitored by a photodetector set at the end of the air injection nozzle. (Refer to Japanese Patent Publication No. 47-36335).

However, according to the above configuration, the propagation path of the flame light is shared with the air injection nozzle, and its tip opening is open to the fuel injection nozzle, so the photodetector is not exposed to the high temperature and high pressure flame inside the combustion chamber. There is a risk that it may be damaged.

In addition, the inner peripheral surface of the flame light introduction part, which is shared with the air injection nozzle, is burnt out or contaminated by the flame inside the combustion chamber, and it cannot be easily attached or detached, making it difficult to accurately detect subtle changes in the flame inside the combustion chamber. Therefore, there is a risk that it will not be possible to accurately monitor whether the flame in the combustion chamber is blown out.

Additionally, a structure has been proposed in which a fiber optic cable is inserted coaxially directly into a combustion injection nozzle such as a gas burner, and the flame inside the combustion chamber is monitored using detection light from the fiber optic cable. (See Japanese Patent Application Laid-Open No. 60-82720).

However, when a flame monitoring device is configured by directly inserting an optical fiber cable into a fuel injection nozzle as in the above configuration, the tip of the optical fiber cable may be exposed to high temperature and high pressure flame and welded.
The problem is that the flame inside the combustion chamber cannot be effectively monitored because it is damaged by repeated violent vibrations due to high-speed turbulent gas.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a flame monitoring device for a gas turbine that has a simple configuration and can effectively and reliably monitor the flame within a combustion chamber.

[Means to solve the problem]

In the flame monitoring device for a gas turbine according to the present invention, a first flame light guide pipe is inserted concentrically through a nozzle chip that injects fuel into a combustion chamber and a fuel nozzle, and the outer circumferential surface of the flame light introduction part at the tip of the first flame light guide pipe is inserted into the nozzle chip. The air is airtightly fixed to the tip of the flame light introduction part, and the inner peripheral surface of the flame light introduction part is opened into the combustion chamber, and the air on the swirler and the air inflow side is introduced into the inner peripheral surface of the flame light introduction part. An introduction hole is provided, the other end of the first flame light guide pipe is moved by a support member, and a second flame light guide pipe is connected to the other end, so that the flame formed by each of the flame light guide pipes is It is characterized by hermetically closing the optical path with a transparent window.

[Effect]

In the above configuration, the flame light caused by combustion in the combustion chamber can be guided to the outside from the flame light introduction part at the tip of the first flame light guide pipe through each flame light guide pipe. The inside of the combustion chamber and the flame can be accurately monitored.

〔Example〕

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

FIG. 1 shows an embodiment of an industrial gas turbine. Here, 1 is a combustor, which is one of the multi-can types described above, and the drawing shows an inner cylinder 6 and a swirler 7.

8 is a housing that covers the inner cylinder 6, and a combustion nozzle 9
is attached via a mounting flange 10. The combustion nozzle 9 is of a straight type, and a nozzle tip 12 having a fuel injection hole 11 and a joint 1 supporting the nozzle tip 12 extend from its tip.
3 and a nozzle body 14 connected to the joint 13, and the mounting flange 10.
It has a support body 15 on the rear side.

Inside such fuel nozzle 9, fuel nozzle 9
A flame monitor A is provided to penetrate in the axial direction.

That is, in this flame monitor A, a support part 16 is provided inside the left end of the support body 15 in the figure, and a first flame light guiding pipe 17 is attached between the support part 16 and the tip of the nozzle tip 12. It is being

A flame light introduction section 19 is set at the tip of the first flame light guiding pipe 17 on the combustion chamber 18 side.

On the other hand, the left end of the first flame light guide pipe 17 is slidable on the support portion 16.
20 is a second flame light guide pipe with a protruding flange 2
1 and a bellows 22, one end is fitted into a first flame light guiding pipe 17 which is thermally expandable and contractible.
A purge air tube 23 is connected to its outer periphery.

A supporting metal fitting 24 is attached to the other end of the second flame light guide pipe 20, and the supporting metal fitting 24 is provided with a pressure-resistant glass (quartz glass) 25, an adapter 26, and a light detection section 27. , an optical fiber cable 28 is connected to the light detection section 27 .

Here, the symbol F in the diagram indicates fuel.

Furthermore, 30 is an air introduction hole, and the nozzle tip 1
Supplying a small amount of air to the flame light introducing section 19 of No. 2,
The purpose is to blow away soot and the like that accumulates in the flame light introduction section 19, and in this case, a small amount of air is supplied by utilizing the pressure difference between the inside and outside of the combustor 1. It is also possible to supply the above and a small amount of air from a special air source, in which case the purge air tube 23 can be used.

In the above configuration, the fuel F passed through the fuel nozzle 9 and injected from the fuel injection hole 11 of the nozzle tip 12 is mixed by the swirling air flow swirled by the swirler 7 and combusted in the combustion chamber 1 of the inner cylinder 6. let

The flame light based on the combustion in the combustion chamber 1 is
From the flame light introduction part 19 at the tip of the first flame light guide pipe 17 to each flame light guide pipe 17, 20
Through this, the flame inside the combustion chamber 1 can be properly monitored.

That is, according to the above configuration, the flame light propagation path includes the first flame light guide pipe 17 which is inserted concentrically through the nozzle tip 12 and the fuel nozzle 9 that inject fuel into the combustion chamber 1, and the first flame light guide pipe 17 which is connected thereto. It is composed of a second flame light guide pipe 20, and is separate and airtightly isolated from the fuel F flow paths 9 and 12, and furthermore, the inside of the combustion chamber 1 and the outside of the housing 8 are connected to each other by a transparent window. In other words, here the pressure-resistant glass 2
5, there is no risk of the optical fiber cable 28 being exposed to the high-temperature, high-pressure flame in the combustion chamber 1 and being welded, or being damaged by repeated violent vibrations due to high-speed turbulent gas. , the flame within the combustion chamber 1 can be accurately monitored with a simple configuration.

Moreover, since the air on the air inflow side of the swirler 7 is introduced into the inner circumferential surface of the flame light introduction part 19 through the air introduction hole 30, the flame light introduction part 19 is constantly exchanged heat with the air, and combustion There is no risk of being burned out by the flame in the combustion chamber 1, and the inner circumferential surface of the flame light introduction part 19 is constantly cleaned by air and is not contaminated, so subtle changes in the flame in the combustion chamber 1 can be avoided. It is also possible to detect with high accuracy, and to monitor whether or not the flame in the combustion chamber 1 is blown out.

Furthermore, since the other end of the first flame light guiding pipe 17 is slidably supported by the support part 16 of the support body 15, the flame light introducing part 19 is overheated by the flame in the combustion chamber 1 and thermally expands. Even if
Since the thermal expansion can be absorbed and the damage can be effectively prevented, and since the second flame light guide pipe 20 is connected to the other end, it can be removed for maintenance and inspection of the flame monitor A. etc. can be easily achieved.

For example, in the embodiment shown in FIG. 1, monitoring is carried out through the optical fiber cable 28, but a type in which the pressure-resistant glass 25 is directly viewed may also be used. (not shown) or by converting visible light electrically.

〔Effect of the invention〕

As described above, according to the present invention, the flame light propagation path includes a first flame light guide pipe that is concentrically inserted through the nozzle chip and the fuel nozzle that inject fuel into the combustion chamber, and a second flame light guide pipe that is connected thereto. It consists of a flame light guide pipe, which is separate and airtight from the fuel flow path, and because the combustion chamber and the outside are airtightly closed off by a light-transmitting window, it is not possible to connect, for example, an optical fiber cable. Even if it is set in the propagation path of the flame light, if it is outside the transparent window, it may be exposed to the high temperature and high pressure flame in the combustion chamber 1 and welded, or it may be caused by high speed turbulent gas. There is no risk of damage due to repeated violent vibrations, and the flame inside the combustion chamber can be accurately monitored with a simple configuration.

In addition, since the air on the air inflow side of the swirler is introduced into the inner peripheral surface of the flame light introduction part through the air introduction hole, the flame light introduction part is constantly exchanged heat with the air, and is heated by the flame in the combustion chamber. There is no risk of damage, and since the inner circumferential surface of the flame light introduction part is constantly cleaned by air and is not contaminated, it is possible to accurately detect subtle changes in the flame inside the combustion chamber. It is possible to accurately monitor whether the flame in the combustion chamber is blown out.

Furthermore, the other end of the first flame light guiding pipe is movably supported by a support member, so that even if the flame light introducing part is overheated by the flame in the combustion chamber and thermally expands, the thermal expansion can be effectively absorbed. In addition, since the second flame guide pipe is connected to the other end, it can be removed to easily perform maintenance and inspection of the flame monitor. .

[Brief explanation of drawings]

FIG. 1 is a sectional view of a flame monitoring device according to a first embodiment of the present invention, and FIG. 2 is a sectional view of a conventional flame monitoring device. 1...Combustor, 6...Inner cylinder, 7...Swirler, 9
... Fuel nozzle, 11 ... Fuel injection hole, 12 ...
nozzle tip, 15... support member, 17... first
Flame light guide pipe, 18... Combustion chamber, 19... Flame light introduction section, 20... Second flame light guide pipe, 2
5...Transparent window (pressure resistant glass), 30...Air introduction hole, F...Fuel, A...Flame monitor.

Claims (1)

[Claims] 1 An inner cylinder forming a combustion chamber, a swirler set at the other end of the inner cylinder, and a nozzle chip having a fuel injection hole set at the axial center of the swirler to inject fuel into the combustion chamber. and a fuel nozzle that supplies fuel to the nozzle chip, and the fuel injected from the fuel injection hole of the nozzle chip through the combustion nozzle is mixed by the swirling air flow swirled by the swirler and combusted in the combustion chamber. In a gas turbine flame monitoring device configured to monitor the flame of a gas turbine, the flame light introducing portion is inserted concentrically through the nozzle tip and the fuel nozzle, and the outer circumferential surface of the flame light introducing portion at the tip is hermetically fixed to the tip of the nozzle tip. a first flame light guide pipe in which the inner circumferential surface of the flame light introducing section is opened into the combustion chamber; and air for introducing air on the air inflow side of the swirler into the inner circumferential surface of the flame light introducing section. an introduction hole, a support member movably supporting the other end of the first flame guide pipe, a second flame guide pipe connected to the other end of the first flame guide pipe, and each of the flames. A light-transmitting window that airtightly closes the flame light path formed by the light-guiding pipe is provided, and the light is transmitted through the light-transmitting window, the second flame light guide pipe, and the first flame light guide pipe to the inner circumferential surface of the tip thereof. A flame monitoring device for a gas turbine, characterized in that the flame inside the combustion chamber is monitored from a flame light introducing section.