JP2000291448A - Gas turbine combustion apparatus and flame backflow detection method thereof - Google Patents

Abstract

(57) Abstract: Provided is a gas turbine combustion device capable of instantaneously detecting a backflow of a flame to a burner and sufficiently preventing burnout of a premixed burner. The diffusion combustion burner is disposed at the axial center of a combustion chamber, a diffusion fuel supply system for supplying fuel to the diffusion combustion burner, and a premix combustion burner disposed around the diffusion combustion burner. In a gas turbine combustion system having a premixed fuel supply system for supplying fuel to the premixed combustion burner, a pressure detection device 19 for detecting a pressure inside the combustor, and an output of the pressure detection device, A flame backflow judging device 21 for judging that the flame has flown back into the burner based on the signal, and a supply flow rate of the diffusion fuel supply system and the premixed fuel supply system is controlled based on a judgment output signal of the flame backflow judgment device. The fuel control device 22 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine combustion apparatus and a method for detecting a flame backflow, and more particularly to a gas turbine combustion apparatus, in which a diffusion combustion burner is arranged at the axial center of a combustion chamber, and a premix combustion burner is arranged around the diffusion combustion burner. The present invention relates to a gas turbine combustion device.

[0002]

2. Description of the Related Art In general, most gas turbine combustion devices for power generation are composed of a mixed combustion system of a diffusion combustion system having excellent combustion stability and a premix combustion system effective for reducing NOx. It is common practice to increase the combustion ratio, that is, to reduce NOx in all premixed combustion or in a state close to it.

On the other hand, in a gas turbine combustor configured to perform such combustion, in a premixed burner (premixed combustion burner), a so-called flame return phenomenon in which a flame flows backward inside the burner easily occurs. This flame return phenomenon occurs when the premixed flame becomes unstable for some reason or when the fuel / air ratio (= fuel flow rate / air flow rate) of the premixed burner increases. If the flame regurgitates, the premix burner will burn in a matter of seconds and the burned parts will cause serious damage, such as damage to downstream gas turbine blades.

[0004] For this reason, conventionally, various measures have been devised for a flame holding structure for holding a flame to improve the stability of the flame,
Further, a device for optimizing the fuel-air ratio of the premix burner has been provided to prevent the flame from returning.

However, it is conceivable that abnormal combustion may occur due to malfunction of the fuel supply system or air supply system, and the flame may flow back to the premix burner. Therefore, a technique for detecting the flame return of the premix burner is required. . As one of the conventional techniques for detecting the flame return of the premix burner, a thermocouple is installed in the premix burner, the metal temperature of the premix burner is detected, and the flame return is determined. There is one in which a supply system is controlled to prevent burnout of a premix burner.

[0006]

SUMMARY OF THE INVENTION In a gas turbine combustor provided with a flame return detector configured as described above, flame return is detected by monitoring a signal of a thermocouple installed in a premix burner. Although it is possible,
However, as a result of the close experiment, it has become clear that this has the following problems.

That is, in the conventional flame return detection device or method, as described above, the metal temperature of the premix burner is detected by the thermocouple installed in the premix burner, and the flame return is determined. In many cases, the thermocouple is embedded in a flame stabilizer provided at the flow path wall surface or at the outlet of the premix burner so as not to disturb the air flow inside the premix burner. For this reason, it takes time before the thermocouple starts to rise in temperature after the flame flows back into the premix burner, and the structure with a small heat capacity starts burning before the thermocouple reaches the flame return judgment temperature. That is, there is a danger that

In a combustor designed to increase the premixed combustion ratio during high-load operation, the premix burner is divided into a plurality of sectors in order to suppress the generation of unburned components during low-load operation. In the case of such a combustor, a thermocouple must be installed for each sector, and a large number of thermocouples are required in the case of such a combustor. In addition, the flame return detecting means becomes complicated, and further, maintenance and inspection of the thermocouple and the like require much time and cost.

The present invention has been made in view of the above, and it is an object of the present invention to provide a simple structure of a flame return detecting unit.
In addition, a gas turbine combustion device of this type is provided which can instantaneously detect that the flame has flowed back into the premix burner and control the combustion state by this detection signal to sufficiently prevent burnout of the premix burner. It is in.

[0010]

That is, the present invention provides a diffusion combustion burner disposed at the axial center of a combustion chamber, a diffusion fuel supply system for supplying fuel to the diffusion combustion burner, and the same combustion as the diffusion burner. A gas turbine combustion device comprising: a premixed combustion burner disposed indoors and around a diffusion combustion burner; and a premixed fuel supply system for supplying fuel to the premixed combustion burner. A pressure detector for detecting the pressure inside the vessel, a flame backflow discriminator for judging that the flame has flown back into the premixed combustion burner based on an output signal of the pressure detector, and a discrimination output of the flame backflow discriminator. A fuel control device for controlling the supply flow rates of the diffusion fuel supply system and the premixed fuel supply system based on signals is provided to achieve the intended purpose.

In this case, the internal pressure of the combustor detected by the pressure detecting device may be an absolute pressure in the premixed combustion burner or in the combustion chamber, a differential pressure between two different points of the premixed combustion burner, or This is a pressure difference between two different points in the combustion chamber.

Further, the present invention provides a diffusion combustion burner disposed at the axial center of a combustion chamber, a diffusion fuel supply system for supplying fuel to the diffusion combustion burner, and a diffusion combustion burner in the same combustion chamber as the diffusion burner. A premixed combustion burner disposed around the burner, a premixed fuel supply system for supplying fuel to the premixed combustion burner, and an air supply system for supplying compressed air for combustion from an air compressor to the burner. In the gas turbine combustion device provided, a pressure detection device for detecting a pressure inside the combustor and a determination that the flame has flowed back into the premixed combustion burner based on an output signal of the pressure detection device. A flame backflow discriminating device and a fuel control device for controlling supply flow rates of the diffusion fuel supply system and the premixed fuel supply system based on a discrimination output signal of the flame backflow discriminating device are provided. Those were.

In this case, the internal pressure of the combustor detected by the pressure detecting device may be the absolute pressure of the inside of the premixed combustion burner or the combustion chamber, or the air flow path of the air supply system or the premixed combustion burner. Fluctuating pressure inside or in the combustion chamber, or differential pressure between the air flow path and the combustion chamber of the air supply system, or differential pressure between the premixed combustion burner and the combustion chamber, or the difference between the air compressor outlet and the combustion chamber. Pressure or the differential pressure between the combustion chambers of adjacent combustors, or two different premixed combustion burners.
It is the differential pressure between points or the differential pressure between two different points in the combustion chamber.

In this case, the determination by the determination device is made based on both the pressure information from the pressure detection device and the operation information of the gas turbine.

Also, the present invention provides a diffusion combustion burner disposed at the axial center of a combustion chamber, a diffusion fuel supply system for supplying fuel to the diffusion combustion burner, and a diffusion combustion burner in the same combustion chamber as the diffusion burner. In a method for detecting a flame backflow of a gas turbine combustion device comprising a premixed combustion burner disposed around a burner and a premixed fuel supply system for supplying fuel to the premixed combustion burner, the device includes a combustor A pressure detection device for detecting the internal pressure; and a flame backflow determination device for determining that the flame has flown back into the premixed combustion burner based on an output signal of the pressure detection device. A flame return determination reference value is set for each of the physical quantities such as the pressure, the fluctuation pressure, and the differential pressure. Determined value, is obtained so as to determine the flame backflow by comparing the average value.

That is, in the gas turbine combustion device formed as described above, the combustion device includes a pressure detection device for detecting a pressure inside the combustor, and an internal pressure of the premixed combustion burner based on an output signal of the pressure detection device. And a fuel control device that controls the supply flow rates of the diffusion fuel supply system and the premixed fuel supply system based on a determination output signal of the flame backflow determination device. Therefore, since the flame return determination is performed by detecting the pressure change, the backflow of the flame is detected instantaneously, and the configuration of the flame return detection unit is simple. Further, since the flame return to the premixer is determined instantaneously, the diffusion fuel supply system and the premix fuel supply system are controlled at an early stage, so that the burnout of the premixer can be sufficiently prevented.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 is a diagram showing a main portion of a gas turbine plant provided with the gas turbine combustion device. 1 is a gas turbine, 2 is a compressor, and 3 is a combustor. In addition, 7 is a generator, 16 is a diffusion fuel supply system, 17 is a premixed fuel supply system, and 19 is a pressure detector.

This gas turbine plant mainly comprises a gas turbine 1, a compressor 2 connected to the gas turbine 1 to obtain compressed air for combustion, a combustor 3, and the like. The compressed air discharged from the compressor 2 is guided to the combustor 3 and burns together with fuel in a combustion chamber 5 formed inside the combustor inner cylinder 4. The combustion gas generated by the combustion is injected into the gas turbine 1 via the transition piece 6, drives the gas turbine 1, and is configured to generate power by the generator 7 connected to the gas turbine.

The main structure of the combustor 3 is composed of a fuel supply system and an air supply system, which are mounted on a pressure vessel 10 hermetically closed by an outer cylinder 8 and an end cover 9. An auxiliary chamber 11 having a smaller diameter than the inner cylinder 4 is provided at an upstream position of the combustor inner cylinder 4, a diffusion fuel nozzle 12 is installed at an upstream position of the sub chamber 11, and an outer circumferential position of the sub chamber 11 is provided. Is provided with a premixer 13.

At an upstream position of the premixer 13, a premixed fuel nozzle 14 is installed, and at a downstream position, a flame stabilizer 15 for stabilizing the premixed flame is installed. Diffusion fuel nozzle 12
A pre-mixed fuel supply system 16 for controlling the pre-mixed fuel flow rate is disposed in the pre-mixed fuel nozzle 14, and a pre-mixed fuel supply system 17 for controlling the pre-mixed fuel flow rate.

In the first embodiment according to the present invention, a pressure conduit 18 and a pressure detector 19 for detecting the pressure of the combustion chamber 5 are installed in the outer cylinder 8, and the pressure information of the combustion chamber from the pressure detector 19 and the gas Based on the gas turbine operation information from the turbine operation control device 20, a judging device 21 for judging that the flame has flowed back to the premixer 13 is installed, and the diffusion fuel supply system 16 And a fuel control device 22 for controlling the flow rate of fuel flowing to the premixed fuel supply system 17.

The operation method of the gas turbine combustor to which the present invention is applied is such that the gas turbine combustor is operated in a diffusion combustion mode having excellent combustion stability in a low load region from the start of the gas turbine, and is operated in a premix combustion in a high load region. The combustion ratio is increased or the diffusion fuel is shut off to perform a full premix operation to reduce NOx. However, when the premix combustion ratio is increased, the fuel-air ratio (= fuel flow rate / air flow rate) of the premixer 13 increases,
It is conceivable that combustion oscillation in which the pressure inside the combustion chamber periodically fluctuates or a flame return phenomenon in which the flame flows back into the premixer 13 is likely to occur.

FIG. 2 schematically shows the pressure behavior of the combustion chamber when a flame return occurs in the premixer. When the flame flows back inside the premixer, the flow velocity increases due to the temperature rise inside the premixer, and the combustion loss accompanying this increases, so that the air flow rate flowing into the premixer decreases, and as a result, the combustion chamber Is reduced (pressure C) as shown in FIG. Further, although the flow rate of the air flowing into the premixer decreases, the decreasing rate of the fuel flow rate supplied to the premixer is smaller than the air flow rate, so that the fuel-air ratio inside the premixer increases, thereby causing a combustion loss. Therefore, the flow rate of the air flowing into the premixer further decreases, and the pressure in the combustion chamber also decreases.

The combustion oscillation in which the pressure in the combustion chamber periodically fluctuates occurs when the air column resonance frequency of the combustion chamber and the fluctuation cycle of the flame approach each other, and the frequency and amplitude of the combustion oscillation depend on the position where the flame is formed. And the length of the flame. Therefore, when the flame flows back into the premixer, the combustion oscillation may change from the pressure amplitude A to the pressure amplitude B, for example, when the flame fluctuates at the pressure amplitude A.

In the present embodiment, the flame return is determined by detecting the pressure drop of the combustion chamber 5 and the change in the amplitude of the combustion oscillation caused by the backflow of the flame into the premixer 13 by the pressure detector 19.

Here, a method for determining the return of the flame based on the pressure drop of the combustion chamber will be described. When the pressure C reduced by the flame return is larger than a predetermined reference value, it is determined that the flame has returned. However, when combustion vibration or the like has occurred,
It is also conceivable that the reference value is exceeded due to fluctuations in combustion oscillation. Therefore, comparing the average value of the pressures for several seconds before and after with reference to the time when the flame return is determined, and determining the flame return based on this value is effective in increasing the determination accuracy.

The method of determining the return of the flame based on the amplitude value of the combustion oscillation is as follows. That is, since the change of the combustion oscillation behavior due to the flame return is considered to be different depending on the combustor and the combustion condition, it is necessary to grasp the combustion oscillation behavior at the time of the flame return in advance, and provide a criterion in consideration of the characteristics. . FIG. 2 shows an example in which the amplitude value of the combustion oscillation is reduced by the flame return. In this example, when the change in the amplitude A exceeds the reference value, it is determined that the flame has returned. Also,
In order to improve the determination accuracy, the return of the flame is determined by comparing the average values of the amplitudes for several seconds before and after based on the time when the return of the flame is determined.

Further, since the pressure and combustion vibration of the combustion chamber fluctuate when the fuel flow rate or air flow rate changes, the determination of the flame return requires the gas turbine operation control device 20 in addition to the combustion chamber pressure information of the pressure detector 19. The determination is performed by the determiner 21 on the basis of the gas turbine operation information such as the fuel flow rate and the air flow rate.
When it is confirmed from these information that a flame return has occurred in the premixer 13, the fuel control device 22 instantaneously controls the flow rate of fuel flowing through the diffusion fuel supply system 16 and the premix fuel supply system 17, and 13 to prevent burning.

The pressure drop in the combustion chamber 5 that occurs when the premixer 13 returns to the flame occurs simultaneously with the return of the flame, and the pressure detector 19 that detects the pressure drop responds as compared with the conventional detection method using a thermocouple. Quickness. For this reason, since it is possible to instantaneously determine the return of the flame and control the fuel flow rate, it is possible to prevent a structure having a small heat capacity from burning out.

Further, in the case of the detection method using a thermocouple, it is impossible to detect the flame return unless the metal temperature of the portion where the thermocouple is installed rises. For example, a premixer without the thermocouple is installed. It is impossible to detect a flame return even if a flame return occurs in a certain portion. However, when flame return is detected by detecting the pressure behavior of the combustion chamber 5 as in the present embodiment, even if a flame return occurs in a part of the premixer, the pressure of the combustion chamber 5 fluctuates due to the influence. Therefore, it is possible to easily detect the flame return.

In this embodiment, the method of detecting the flame return by detecting the pressure drop of the combustion chamber 5 and the change of the amplitude of the combustion oscillation by the pressure detector 19 has been described. It is also possible to judge from the pressure drop and the gas turbine operation information.

Next, a second embodiment according to the present invention will be described with reference to FIG. The basic components of the second embodiment are the same as those of the first embodiment, and a pressure conduit 23 for detecting the pressure on the upstream side of the premixer 13 is installed in the outer cylinder 8 to reduce the pressure of the combustion chamber 5. A differential pressure gauge 24 for detecting a differential pressure with the pressure conduit 18 to be detected.
Is provided.

The pressure in the combustion chamber 5 in the high load region of the gas turbine combustor to which the present invention is applied is several tens of atmospheres, which is much higher than the pressure C which decreases when the premixer 13 returns to the flame. Therefore, in order to detect the pressure drop at the time of flame return by the pressure transducer 19 having a large measurement range for detecting the pressure of the combustion chamber 5, the detection accuracy needs to be improved.

The second embodiment solves this problem, and is configured to detect a pressure drop at the time of flame return by a differential pressure between the combustion chamber 5 and the upstream side of the premixer 13. As described above, when the flame returns to the premixer 13, the pressure loss of the premixer 13 increases, and it becomes difficult for air to flow into the premixer 13, so that the pressure in the combustion chamber 5 decreases. On the other hand, since the influence hardly spreads to the pressure on the upstream side of the premixer 13, the pressure hardly changes before and after the flame return. Therefore, the pressure difference between the combustion chamber 5 and the upstream side of the premixer 13 that occurs when the flame returns to the premixer 13 is increased, and the detection accuracy is improved. Accordingly, the accuracy of the determination unit 21 for determining the return of the flame is improved, so that the burnout of the premixer 13 due to the return of the flame can be prevented.

In this embodiment, a variable pressure gauge 25 having excellent frequency response is installed at the end of the pressure conduit 18 for detecting the pressure of the combustion chamber 5. Since the amplitude change can be detected with high accuracy, it is possible to improve the flame return determination accuracy of the discriminator 21. For this reason, by superimposing and examining the pressure information from the differential pressure gauge 24 and the variable pressure information from the variable pressure gauge 25, an effect equal to or greater than that of the first embodiment can be expected.

In this embodiment, the pressure drop of the combustion chamber 5 is detected by the differential pressure gauge 24, and the change in the amplitude of the combustion vibration of the combustion chamber is detected by the variable pressure gauge 25, and the flame return is determined from the information and the gas turbine operation information. Although the method of performing the flame return has been described, it is also possible to determine the return of the flame based on the pressure information and the gas turbine operation information from the differential pressure gauge 24 or the fluctuation pressure information and the gas turbine operation information of the fluctuation pressure gauge 25.

Further, in this embodiment, the pressure drop in the combustion chamber 5 due to the flame return of the premixer 13 is detected by the pressure difference between the combustion chamber and the upstream position of the premixer. The effect of the present invention can be exerted in any of the inside of the premixer 13 or the compressor outlet, and the combustion chamber of another combustor.

Next, a third embodiment according to the present invention will be described with reference to FIG. The third embodiment is an example in which the present invention is applied to a combustor designed to increase the premixed combustion ratio in a high load region. In such a combustor, generation of unburned components in a low load region is performed. In order to suppress such a problem, a method of dividing the premixer into a plurality of sectors and controlling the number of burning sectors according to the load has been adopted.

A diffusion combustion swirl burner 26 for performing diffusion combustion is provided at the axial center of the combustor, and a plurality of premixing swirl burners 27 are arranged at the outer peripheral position.
6 is provided with a diffusion fuel supply system 16, a premixed fuel nozzle 29 of a premixed swirl burner 27 is provided with a premixed fuel supply system 17, and an outlet of the premixed swirl burner 27 is provided at an outlet thereof. A swivel 30 is provided.

In this embodiment, a pressure conduit 31 is provided in the outer cylinder 8 of such a combustor, and other components are the same as those in the second embodiment. The pressure conduit 31 is formed as a double pipe, and the inner peripheral pressure conduit is configured to detect the pressure in the combustion chamber 5, and the outer peripheral pressure conduit is configured to detect the pressure in the upstream portion of the premixer 13. The inner pressure pipe is connected to the differential pressure gauge 24 and the variable pressure gauge 25, and the outer pressure pipe is connected to the differential pressure gauge 24. With the configuration as described above, it is possible to obtain the same effect as in the second embodiment.

Further, in the combustor of this embodiment, the operation of sequentially burning each sector according to the load is performed. In such an operation method, flame return occurs in a specific sector when the load increases. It is possible. When the flame return occurs in one of the plurality of divided sectors, the amount of pressure change generated in the combustion chamber 5 is small, but as in this embodiment, the combustion chamber 5 and the upstream portion of the premixer are different from each other. Since the measurement accuracy of the pressure behavior can be improved by measuring the differential pressure, it is possible to determine the flame return to the premixer 13 even in such a case.

Further, in this embodiment, since the pressure conduit 31 is formed in a double structure, it is not necessary to form a plurality of differential pressure measurement holes in the outer cylinder 8, and the number of pressure conduits can be reduced by half, so that the preparation for measurement is reduced. And costs related to maintenance and inspection can be reduced.

Next, a fourth embodiment of the present invention will be described with reference to FIG. As in the third embodiment, this embodiment is an example in which the present invention is applied to a combustor designed to increase the pre-combustion ratio in a high load region. The first to third embodiments show an example in which the present invention is applied to a combustor using a diffusion burner excellent in combustion stability as a pilot burner and a premix burner capable of reducing NOx as a main burner. However, in the fourth embodiment, a diffusion burner and a premix burner are used for the pilot burner and a combustor using the premix burner for the main burner in order to suppress the generation of NOx in a low load region. It is an application of the invention.

A diffusion combustion swirl burner 32 for performing diffusion combustion is provided at the axial center of the combustor, a premix swirl burner 33 for a pilot burner is provided at an outer peripheral position thereof, and a premix burner for a main burner is provided at an outer peripheral position thereof. A swirling blade 35 is installed at a position upstream of the premix swirling burner 33 for the pilot burner, and a premix fuel nozzle 36 is installed at a downstream position thereof. A fuel supply system 37 is provided.

In this embodiment, the outer cylinder 8 of such a combustor is used.
Next, a pressure conduit 31 similar to that of the third embodiment is installed. The pressure in the combustion chamber 5 is detected by the pressure conduit 31, the flame return of the premix burner 34 for the pilot burner or the premix burner 33 for the main burner is detected, and the premix fuel supply systems 17, 37 are controlled by the fuel control device 22. By controlling, an effect equivalent to that of the third embodiment can be obtained.

In the combustor of this embodiment, the premix burner 34 for the pilot burner is burned even at a partial load. However, when the premix burn is performed during the partial load operation in which the combustion state changes drastically, unstable combustion occurs. Although it is conceivable that a flame return may occur due to the occurrence of a flame return, the measurement accuracy of the pressure behavior is improved by measuring the differential pressure between the combustion chamber 5 and the upstream part of the premixer as in the present embodiment. Therefore, even in such a case, it is possible to determine the flame return of the pilot burner premix burner 34.

Further, in the combustor to which this embodiment is applied, in the high load region, the premix burner 34 for the pilot burner is used.
And the main burner premix burner 33 is burned. However, in this embodiment, the measurement accuracy of the pressure behavior can be improved. Therefore, even if a flame return occurs in any of the premix burners, the flame return occurs. Can be determined.

Next, a fifth embodiment according to the present invention will be described with reference to FIG. The main components of the gas turbine combustor of this embodiment are the same as those of the second embodiment. In this embodiment, the pressure conduits 18 and 38 for detecting the pressure in the combustion chamber 5 are connected to the combustion chamber 5.
Are arranged at different positions in the axial direction, and the differential pressure in the axial direction of the combustion chamber is detected by the differential pressure gauge 24.

The premixed flame 39 held by the flame stabilizer 15 installed in the premixer 13 as in the present embodiment is formed by the position where the flame is formed and the flame shape depending on the fuel-air ratio of the premixer 13 and the like. When the fuel-air ratio of the premixer 13 increases, the spread angle of the premixed flame 39 increases, so that the position where the premixed flame 39 comes into contact with the inner cylinder 4 approaches the premixer 13. It is shown. Since flame return easily occurs when the flame approaches the premixer, the present embodiment detects the position where the premixed flame 39 is formed from the pressure difference in the axial direction of the combustion chamber 5 and sends the premixed flame 39 to the premixer 13. The flame is prevented from returning.

The relationship between the position where the premixed flame 39 is formed and the output signal of the differential pressure gauge 24 will be described. Premixed flame 3
If 9 were formed between the pressure lines 18 and 38, the premixed flame 39 would increase the temperature and increase the flow rate, thereby increasing the combustion losses. For this reason, the pressure in the pressure conduit 18 installed at a position upstream of the premixed flame 39 is higher than that of the pressure conduit 38 installed at a position downstream of the premixed flame 39, so that the differential pressure increases.

Next, when the fuel-air ratio of the premixer 13 increases and a premixed flame 39 is formed upstream of the pressure conduit 18,
Since the pressure in the pressure conduit 18 is substantially equal to the pressure in the pressure conduit 38 installed on the downstream side, the differential pressure is reduced.

Therefore, it is possible to predict the formation position of the premixed flame 39 by detecting the pressure at different positions in the axial direction of the combustion chamber 5 with the differential pressure gauge 24. As described above, when the premixed flame 39 approaches the premixer 13, the flame easily returns to the premixer 13.
The flame formation position is determined by the determiner 21 based on the differential pressure information, and the fuel control device 22 is controlled based on this information to prevent the flame from returning to the premixer 13 beforehand.

As described above, in the gas turbine combustion apparatus formed as described above, since the flame return detection is performed by detecting the pressure change, the configuration of the flame return detection section is simple, and the combustion chamber By detecting the pressure, the flame return of the premixer can be instantaneously determined. As a result, by controlling the diffusion fuel supply system and the premix fuel supply system, the premixer can be sufficiently prevented from burning. This makes it possible to improve the reliability of the gas turbine combustion device.

[0054]

As described above, according to the present invention, the structure of the flame return detecting section is simple, and it is instantaneously detected that the flame has flowed back to the premix burner, and the detection signal indicates the combustion state. , A gas turbine combustion apparatus of this kind that can sufficiently prevent burnout of the premix burner can be obtained.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing a gas turbine plant provided with a gas turbine combustor device of the present invention.

FIG. 2 is an explanatory diagram of a combustion chamber pressure behavior at the time of flame return.

FIG. 3 is a vertical sectional side view showing a second embodiment of the gas turbine combustor device of the present invention.

FIG. 4 is a vertical sectional side view showing a third embodiment of the gas turbine combustor device of the present invention.

FIG. 5 is a vertical sectional side view showing a fourth embodiment of the gas turbine combustor device of the present invention.

FIG. 6 is a vertical sectional side view showing a fifth embodiment of the gas turbine combustor apparatus of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas turbine, 2 ... Compressor, 3 ... Combustor, 16 ... Diffusion fuel supply system, 17 ... Premixed fuel supply system, 18, 23,
31, 38: Pressure conduit, 19: Pressure detector, 20: Gas turbine operation control device, 21: Judgment device, 22: Fuel control device, 24: Differential pressure gauge, 25: Variable pressure gauge.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masaya Otsuka 7-2-1, Omika-cho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Power and Electricity Development Division (72) Inventor Tomoya Murota Omika-cho, Hitachi City, Ibaraki Prefecture 7-2-1, Hitachi, Ltd. Power and Electricity Development Division (72) Inventor Narika Kobayashi 7-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Power and Electricity Development Division (72 ) Inventor Hiroshi Inoue 7-2-1, Omika-cho, Hitachi City, Ibaraki Pref.Hitachi, Ltd. Power and Electricity Development Division (72) Inventor Fumiharu Moriwaki 3-1-1 Sachimachi, Hitachi City, Ibaraki Co., Ltd. Inside the Hitachi Works of Hitachi, Ltd.

Claims (6)

[Claims] 1. A diffusion combustion burner disposed at an axial center of a combustion chamber, a diffusion fuel supply system for supplying fuel to the diffusion combustion burner, and a diffusion combustion burner in the same combustion chamber as the diffusion combustion burner. A gas turbine combustion device comprising: a premixed combustion burner disposed around; and a premixed fuel supply system that supplies fuel to the premixed combustion burner. The device includes: a pressure detecting a pressure inside a combustor. A detecting device, a flame backflow discriminating device for judging that the flame has flown back into the premixed combustion burner based on an output signal of the pressure detecting device, and the diffusion fuel supply based on a discriminating output signal of the flame backflow judging device. A fuel control device for controlling a supply flow rate of a system and a premixed fuel supply system. 2. The combustor internal pressure detected by the pressure detecting device is an absolute pressure inside the premixed combustion burner or a combustion chamber, a differential pressure between two different points of the premixed combustion burner, or a combustion chamber. 2. A pressure difference between two points having different pressures.
The gas turbine combustion device according to any one of the preceding claims. 3. A diffusion combustion burner disposed at an axial center of a combustion chamber, a diffusion fuel supply system for supplying fuel to the diffusion combustion burner, and a diffusion combustion burner in the same combustion chamber as the diffusion combustion burner. A premixed combustion burner disposed around, a premixed fuel supply system that supplies fuel to the premixed combustion burner, and an air supply system that supplies compressed air for combustion from an air compressor to the burner. A gas turbine combustion device, comprising: a pressure detection device that detects a pressure inside a combustor; and a flame backflow that determines that a flame has flown back into the premixed combustion burner based on an output signal of the pressure detection device. A gas controller, comprising: a discriminating device; and a fuel control device for controlling supply flow rates of the diffusion fuel supply system and the premixed fuel supply system based on a discrimination output signal of the flame backflow judging device. Bottle combustion equipment. 4. The internal pressure of the combustor detected by the pressure detecting device may be the absolute pressure of the inside of the premixed combustion burner or the combustion chamber, or the inside of the air flow path or the premixed combustion burner of the air supply system. The fluctuating pressure of the combustion chamber, or the differential pressure between the air flow path and the combustion chamber of the air supply system, or the differential pressure between the premixed combustion burner and the combustion chamber, or the differential pressure between the air compressor outlet and the combustion chamber. The gas turbine combustion apparatus according to claim 3, wherein the pressure difference is a pressure difference between combustion chambers of adjacent combustors, a pressure difference between two different points of a premixed combustion burner, or a pressure difference between two different points of a combustion chamber. 5. The gas turbine combustion apparatus according to claim 1, wherein the determination by the determination device is made based on both the pressure information from the pressure detection device and the operation information of the gas turbine. . 6. A diffusion combustion burner disposed at an axial center of a combustion chamber, a diffusion fuel supply system for supplying fuel to the diffusion combustion burner, and a diffusion combustion burner in the same combustion chamber as the diffusion combustion burner. In a method for detecting a backflow of a flame of a gas turbine combustion device comprising a premixed combustion burner disposed around and a premixed fuel supply system for supplying fuel to the premixed combustion burner, the device includes: A pressure detection device for detecting pressure, and a flame backflow determination device for determining that the flame has flown back into the premixed combustion burner based on an output signal of the pressure detection device are provided, and an absolute pressure from the pressure detection device is provided. For the physical quantities such as the fluctuation pressure and the differential pressure, a flame return determination reference value is set, and based on the time when the value of each physical quantity exceeds the determination reference value, the average value of the physical quantities for a certain period of time before and after is determined.
A flame backflow detecting method for a gas turbine combustion device, characterized in that the average value is compared to determine the flame backflow.