JPH06331146A - Method for measuring pressure within combustion device of gas turbine and device for measuring pressure within it - Google Patents

Abstract

PURPOSE:To prevent a pressure sensor from having troubles by high temperature and further to enable a pressure within a gas turbine combustion device to be accurately measured. CONSTITUTION:A tip of a pressure guide pipe 12 is inserted into an inner cylinder 14 of a combustion device through an outer cylinder 11 of the combustion device. A pressure sensor 15 is fixed to a base end of the pressure guiding pipe 12 through an elbow 13 acting as a fixing part. Since the pressure sensor 15 is placed outside the gas turbine combustion device, it is possible to prevent the pressure sensor 15 from having troubles at a high temperature. An attenuation pipe 14 is fixed to the elbow 13 and a frequency characteristic at a certain part is made flat in its amplitude. A sensing characteristic of this flat amplitude covers a combustion vibration frequency. After an output of the pressure sensor 15 is amplified by an amplifier 16, only the combustion vibration component is passed through a bandpass filter 17. With such an arrangement as above, it is possible to perform an accurate measurement of the pressure within the gas turbine combustion device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure measuring method and a pressure measuring apparatus in a gas turbine combustor, and more particularly to a gas capable of stably measuring pressure fluctuation in the gas turbine combustor for a long period of time. The present invention relates to a pressure measuring method and a pressure measuring device in a turbine combustor.

[0002]

2. Description of the Related Art A combustor of a gas turbine is generally in the shape of a cylinder, and when fuel burns inside the combustor, combustion vibration occurs due to resonance with an air column. This combustion vibration always occurs, although the vibration level is large or small, as long as the phenomenon of combustion occurs. This combustion oscillation occurs with a specific range of oscillation frequency, and depends on the length of the gas turbine combustor and the temperature of the combustion gas,
Since it is restricted from the viewpoint of the combustion performance of the gas turbine combustor, the frequency is around 100 Hz to around 200 to 300 Hz.

Similarly, the diameter and length of the gas turbine combustor are determined from the viewpoint of combustion performance, and the wall thickness is made thin in order to alleviate thermal stress due to rapid temperature rise and change.
Further, in order to absorb the thermal expansion during operation, the support portion of the gas turbine combustor is installed with a considerable gap. In such a state, if the combustion vibration is large or the combustion vibration and the gas turbine combustor resonate with each other, the gas turbine combustor vibrates extremely and excessive wear occurs in each support portion. Moreover, since the members of the gas turbine combustor itself also vibrate, cracking and the like may become a problem due to high cycle fatigue due to vibration stress, and it is important to keep combustion vibrations small at all times.

In order to monitor such combustion oscillation, it is necessary to correctly detect the pressure variation during the combustion oscillation and perform the operation so that the pressure variation during the combustion becomes small. Correct detection of the pressure in the gas turbine combustor is extremely important for the operation in which the pressure fluctuation is small. Therefore, conventionally, a method has been adopted in which a pressure sensor is directly mounted in the gas turbine combustor to measure the pressure fluctuation in the gas turbine combustor.

[0005]

In the conventional pressure measuring method in the gas turbine combustor, since the pressure sensor is directly mounted in the gas turbine combustor, the pressure sensor is in direct contact with the hot combustion gas. If the pressure sensor fails or is damaged, the pressure may not be detected properly. If the pressure detection fails, there is a problem that the operation of the gas turbine combustor thereafter is hindered.

The present invention has been made in consideration of the above-mentioned circumstances, and it is possible to accurately measure pressure fluctuations in a gas turbine combustor over a long period of time with high reliability and accuracy. An object of the present invention is to provide a pressure measuring method and a pressure measuring device.

[0007]

In order to solve the above-mentioned problems, a pressure measuring method in a gas turbine combustor according to the present invention has a tip of a pressure guiding tube with a combustor outer cylinder as described in claim 1. The pressure sensor is attached to the base end side of the pressure guiding tube via the mounting part, while the damping tube is approximately the same diameter as the pressure guiding tube and is longer than the pressure guiding tube. Attached, amplify the output of the pressure sensor with an amplifier,
After that, a pressure detection waveform is obtained through a filter that passes only the frequency component of the combustion vibration, and the pressure in the gas turbine combustor is measured.

In order to solve the above-mentioned problems, the method for measuring the pressure in the gas turbine combustor according to the present invention, as set forth in claim 2, penetrates the tip of the pressure guiding tube through the outer cylinder of the combustor. In the method of measuring the pressure inside the combustor by inserting a pressure sensor on the proximal end side of the pressure guiding tube while inserting the pressure guiding tube into the inner cylinder of the combustor, This is a method of setting the length to be a required multiple of the frequency of.

In order to solve the above-mentioned problems, the method for measuring the pressure in the gas turbine combustor according to the present invention is such that the tip of the pressure guiding tube penetrates the combustor outer cylinder and the tip is Insert it in the combustor inner cylinder, and attach a damping pipe having a diameter almost the same as the pressure guiding pipe and longer than the pressure guiding pipe to the pressure guiding pipe through the mounting portion. A method of measuring pressure, wherein the attenuation pipe has a length that is approximately 8 times or more the length of the pressure guiding pipe.

On the other hand, in order to solve the above-mentioned problems, the pressure measuring device in the gas turbine combustor according to the present invention penetrates the combustor outer cylinder to penetrate the combustor inner cylinder as described in claim 4. A pressure guiding tube having a tip inserted therein, a pressure sensor mounted on the base end side of the pressure guiding tube via a mounting portion, and a pressure sensor mounted on the mounting portion and having substantially the same diameter as the pressure guiding tube A long damping pipe is provided, and the pressure detection waveform is set to be obtained from the output of the pressure sensor through a filter that passes only the frequency component of combustion oscillation.

Further, in order to solve the above-mentioned problems, the pressure measuring device in the gas turbine combustor according to the present invention, as set forth in claim 5, penetrates the tip of the pressure guiding pipe through the combustor outer cylinder. Then, the pressure sensor is attached to the base end side of the pressure guiding tube, and the pressure guiding tube is set such that the primary resonance frequency in the tube is a required multiple of the frequency of combustion oscillation. The pressure inside the gas turbine combustor is measured.

Further, in order to solve the above-mentioned problems,
The pressure measuring device in the gas turbine combustor according to the present invention,
As described in claim 6, a pressure guiding tube which penetrates the combustor outer cylinder and has a tip inserted into the combustor inner cylinder, and a pressure guiding tube which is attached to the pressure guiding tube through a mounting portion and has substantially the same diameter as the pressure guiding tube. And a damping sensor longer than the pressure guiding tube and a pressure sensor attached to the mounting portion.
The length is set to more than double.

[0013]

According to the first and fourth aspects of the present invention, the pressure in the gas turbine combustor is drawn to the outside through the pressure guiding pipe, and the pressure is detected by the pressure sensor on the base end side. . Therefore, the pressure sensor is less likely to be broken or damaged by heat, and even if it should fail, replacement is extremely easy.

By the way, when a pressure guiding tube is used, there is a problem that amplification and damping are significant due to the air column resonance characteristic in the tube, and it is difficult to accurately detect pressure. However, in the present invention, the damping tube is attached to the pressure guiding tube. Since a certain part of the frequency characteristics has a flat amplitude, the detection characteristic range with flat amplitude is matched so as to cover the combustion vibration frequency range, and a filter is used to pass only the combustion vibration component to detect pressure. Obtaining the waveform allows for extremely accurate pressure sensing within the gas turbine combustor.

Further, in the invention described in claim 2 and claim 4 of the present invention, the pressure guiding tube is set to a length such that the primary resonance frequency in the tube is a required multiple of the frequency of combustion oscillation, It is possible to make the pressure tube very short.

Further, claim 3 and claim 6 of the present invention.
In the invention described in (3), the damping tube is set to a length that is approximately eight times or more the length of the pressure guiding tube. For this reason, the resonance frequency in the impulse line exists innumerably from the frequency extremely lower than the frequency of combustion oscillation, but the effective characteristic is that the amplitude of the peaks of resonance / anti-resonance is significantly larger than the detection characteristic. Becomes smaller. Therefore, the pressure can be detected only by the combustion vibration component.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a pressure measuring device for carrying out a pressure measuring method in a gas turbine combustor according to a first embodiment of the present invention. In the figure, reference numeral 1 is air, and this air 1 is It is compressed by the compressor 2 and becomes compressed air 3 which is guided into the combustor inner cylinder (combustor liner) 4. This compressed air 1
Are mixed and diffused with the fuel injected from the fuel nozzle 5, and are ignited by the spark plug 6 and burned. Then, the gas burned in the combustion chamber in the combustor liner 4 becomes the combustion gas 7 which is guided to the turbine portion 8 to perform the work and then becomes the exhaust gas 9 which is released to the atmosphere.

In the gas turbine combustor, generally, a combustor inner cylinder 4 for causing combustion and its combustion gas 7 are supplied to a turbine section 8.
And a transition piece 10 that guides to the inside of the combustor inner tube 4, as shown in FIG.
A tip end of a pressure guiding tube 12 having an inner diameter of several mm, for example, 4 mm is inserted through the air vent hole of the combustor outer cylinder 11 and penetrates the combustor outer cylinder 11. As shown in FIG. 1 and FIG. 2, an elbow 13 as a mounting portion is mounted.

As shown in FIGS. 1 and 2, a damping pipe 14 and a pressure sensor 15 having the same diameter as the pressure guiding pipe 12 and longer than the pressure guiding pipe 12 are attached to the elbow 13, respectively. The output is amplified by the amplifier 16 and then passed through a bandpass filter 17 that passes only the frequency component of combustion oscillation. Then, the pressure is measured by the pressure measuring means 18 using the output signal that has passed through the band pass filter 17 as a pressure detection waveform. Pressure guide tube 12 and damping tube 14
Respectively constitute detection tubes 20.

Next, the operation of this embodiment will be described.
3A, 3B, and 3C show pressure detection characteristics and pressure detection results with respect to the pressure in the gas turbine combustor in the case of the measuring method of the present embodiment, and FIGS.
(B) and (c) show pressure detection characteristics and pressure detection results with respect to the pressure in the gas turbine combustor when the damping pipe is not attached, that is, when the pressure sensor is attached to the end of the pressure guiding pipe. In the pressure detection characteristic shown in FIG. 4 (b), reference characters f1 and f2 are air column resonance frequencies in the pressure guiding tube, and
These are

[0021]

## EQU1 ## fn = (2n-1) c / 4L where n: sound pressure mode c: sound velocity of medium in pressure guiding tube L: frequency determined by length of pressure guiding tube.

The pressure fluctuation frequency f in the gas turbine combustor shown in FIG. 4 (a) is located between or close to the air column resonance frequencies f1 and f2 in the pressure guiding tube shown in FIG. 4 (b). In this case, as shown in FIG. 4C, the pressure detection result is completely different from the pressure in the gas turbine combustor.

On the other hand, the pressure detection characteristic when the damping tube 14 is connected to the pressure guiding tube 12 has a flat frequency characteristic in a partial region (p1 / p2) as shown in FIG. 3 (b). Become. Therefore, the pressure guiding tube 12 and the damping tube 1 having such characteristics that the flat frequency characteristic region covers the combustion vibration frequency.
Set 4. In order to obtain such characteristics, generally, the damping pipe 14 may be made longer than the pressure guiding pipe 12.

By the way, the detection tube (pressure guiding tube 1 as it is
The characteristics of the 2+ attenuator tube 14) are as shown in FIG.
Since it has a sharp peak and has a plurality of flat amplitude characteristics, it passes through the bandpass filter 17 of an electric circuit in a region that covers only the combustion oscillation frequency component. As a result, the pressure detection result as shown in FIG. 3C is obtained.

Thus, the combustion vibration component can be made clear and accurately detected. In addition, the pressure sensor 15
Is drawn out of the gas turbine combustor through the pressure guiding pipe 12, so that the pressure sensor 15 is placed at a position where the temperature is low.
Can be attached, and the pressure sensor 15 is extremely unlikely to malfunction or break, resulting in poor pressure detection. Even if the pressure sensor 15 fails to be detected, the pressure sensor 15 is located outside the gas turbine combustor, so that replacement is easy.

FIG. 5 shows a second embodiment of the present invention, in which the primary resonance frequency f1 in the pressure guiding tube 21 is a required multiple of the combustion vibration frequency f, for example, 1.4 times. The length of the pressure guiding tube 21 is set so that the length of the pressure guiding tube 21 can be made extremely short. That is, the following equation is established.

[0027]

## EQU2 ## f1 = (2n-1) c / 4L where n: sound pressure mode order c: speed of sound L: length of pressure guiding tube

[0028]

L ≧ (2n−1) c / 4 × 1.4f As a result, the detection characteristic of the pressure guiding tube 21 is sufficiently higher than the combustion vibration frequency f as shown in FIG. Since the combustion vibration component and the resonance vibration component of the pressure guiding tube 21 are detected in an overlapping manner, the cutoff frequency is adjusted by the low-pass filter so that only the combustion vibration component is output. The method of withdrawing the pressure guiding pipe 21 from the gas turbine combustor is the same as in the case of the first embodiment (see FIG. 1).

In this embodiment, however, the low frequency can be detected up to the target frequency with a flat characteristic, but the length of the pressure guiding tube 21 is too short to detect combustion vibration of several hundreds of hertz. I will get sick. Therefore, the applicable range is limited to some extent. However, since the pressure sensor 15 is attached to the outside of the gas turbine combustor, the pressure sensor 1
It is possible to suppress the pressure detection failure due to the failure or damage of No. 5.

FIG. 6 shows a third embodiment of the present invention, in which the damping tube is set to a length of about 8 times or more the length of the pressure guiding tube. That is, the detection method according to the present embodiment, as shown in FIG. 6 (b), is similar to that of the first embodiment.
Although the damping pipe 32 is extended to the pressure guiding pipe 31 and is detected by the pressure sensor 15, unlike the case of the first embodiment,
The attenuation pipe 32 is set to have a length that is approximately eight times or more the length of the pressure guiding pipe 31.

However, in the case of the present embodiment, the resonance frequency in the detection pipe (pressure guiding pipe 31 + attenuation pipe 32) is as shown in FIG.
As shown in (a) and (b), there are innumerable frequencies from a frequency extremely lower than the frequency f of combustion oscillation, but effective characteristics are that the amplitudes of the peaks of the resonance and antiresonance are as shown in FIG. b)
It shows a useful characteristic that is significantly smaller than the detection characteristic shown in (1), and that the amplitude of the peaks of resonance / anti-resonance decreases as the frequency increases. Therefore, the same effect as that of each of the above-described embodiments can be obtained.

[0032]

As described above, according to the first and fourth aspects of the present invention, the pressure in the gas turbine combustor is extracted to the outside through the pressure guiding pipe and detected by the pressure sensor. Therefore, the pressure sensor fails,
There is little risk of damage, and in the unlikely event of failure, replacement is extremely easy.

Further, since the pressure guiding pipe is provided with the damping pipe and only the combustion oscillating component is passed through the filter to obtain the pressure detection waveform, the pressure can be detected extremely accurately. Further, in the inventions according to claims 2 and 5 of the present invention, since the pressure guiding tube is set to have a length such that the primary resonance frequency in the tube is a required multiple of the frequency of combustion oscillation,
The impulse tube can be very short.

Further, claim 3 and claim 6 of the present invention.
In the invention described in (1), since the damping pipe is set to a length that is approximately 8 times or more the length of the pressure guiding pipe, the amplitude of the resonance frequency in the pressure guiding pipe is significantly reduced, and only the fuel vibration component causes pressure Can be detected.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a pressure measuring device for performing a pressure measuring method in a gas turbine combustor according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a portion of the elbow shown in FIG.

3 (a) is an explanatory diagram showing pressure inside the gas turbine combustor of FIG. 1, (b) is an explanatory diagram showing pressure detection characteristics at that time, and (c) is a final pressure detection result. Explanatory drawing.

4 (a) is an explanatory view showing the pressure in the gas turbine combustor of FIG. 1, (b) is an explanatory view showing the pressure characteristics when there is no damping pipe, and (c) is the pressure detection result at that time. FIG.

5A and 5B show a second embodiment of the present invention, in which FIG. 5A is an explanatory diagram showing the pressure inside the gas turbine combustor, FIG. 5B is an explanatory diagram showing the detection characteristics at that time, and FIG. Explanatory drawing which shows the final pressure detection result.

6A and 6B show a third embodiment of the present invention, in which FIG. 6A is an explanatory view showing the pressure inside the gas turbine combustor, FIG. 6B is an explanatory view showing the pressure detection characteristic at that time, and FIG. Is an explanatory view showing a final pressure detection result.

[Explanation of symbols]

 4 Gas Turbine Combustor Inner Cylinder 11 Gas Turbine Combustor Outer Cylinder 12, 21, 31 Pressure Guide Tube 13 Elbow 14, 32 Damping Tube 15 Pressure Sensor 16 Amplifier 17 Band Pass Filter 18 Pressure Detection Means

Claims (6)

[Claims] 1. A tip of a pressure guiding pipe is inserted into a combustor inner cylinder by penetrating a combustor outer cylinder, and a pressure sensor is attached to a base end side of the pressure guiding pipe via a mounting portion, and at the same time, to the mounting portion. An attenuation pipe, which has almost the same diameter as the pressure guiding pipe and is longer than the pressure guiding pipe, is attached, a pressure detection waveform is obtained from the output of the pressure sensor through a filter that passes only the frequency component of combustion oscillation, and the pressure in the gas turbine combustor is measured. A method for measuring pressure in a gas turbine combustor, comprising: 2. The pressure in the gas turbine combustor is measured by inserting the tip of the pressure guiding pipe into the combustor inner cylinder through the combustor outer cylinder and installing a pressure sensor on the proximal end side of the pressure guiding pipe. The method for measuring pressure in a gas turbine combustor according to claim 1, wherein the pressure guiding tube is set to a length such that the primary resonance frequency in the tube is a required multiple of the frequency of combustion oscillation. 3. A damping pipe, wherein the tip of the pressure guiding pipe penetrates the combustor outer cylinder and is inserted into the combustor inner cylinder, and the pressure guiding pipe has a diameter substantially the same as that of the pressure guiding pipe via a mounting portion and longer than the pressure guiding pipe. And measuring the pressure in the gas turbine combustor with a pressure sensor attached to the attachment part, wherein the damping pipe is set to a length of about 8 times or more the length of the pressure guiding pipe. A characteristic method for measuring pressure inside a gas turbine combustor. 4. A pressure guide tube having a tip inserted into the combustor inner cylinder by penetrating the combustor outer cylinder, a pressure sensor attached to the base end side of the pressure guide tube via an attachment portion, and the attachment. Is equipped with a damping pipe that has a diameter substantially equal to that of the pressure guiding pipe and is longer than the pressure guiding pipe, and is set to obtain a pressure detection waveform from the output of the pressure sensor through a filter that passes only the frequency component of combustion vibration. A pressure measuring device in a gas turbine combustor characterized by the above. 5. The tip of the pressure guiding tube is inserted into the combustor inner cylinder by penetrating the combustor outer cylinder, and a pressure sensor is attached to the base end side of the pressure guiding tube, and the pressure guiding tube is connected to the primary pipe in the tube. The pressure measuring device in the gas turbine combustor is characterized in that the resonance frequency is set to a length that is a required multiple of the frequency of combustion oscillation to measure the pressure in the gas turbine combustor. 6. A pressure guiding tube having a tip inserted into the inner tube of the combustor through the outer tube of the combustor, and a pressure guiding tube which is attached to the pressure guiding tube via a mounting portion and has a diameter substantially equal to that of the pressure guiding tube. In a gas turbine combustor, further comprising a long damping pipe and a pressure sensor attached to the mounting portion, and the damping pipe is set to a length of about 8 times or more the length of the pressure guiding pipe. Pressure measuring device.