JPH05240435A - Gas turbine combustion monitoring device - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to enable the gas turbine to operate without unnecessarily stopping even if a failure occurs in the temperature detector T in the gas turbine exhaust chamber. A temperature detector T which is not adjacent to each other among a plurality of temperature detectors T provided on the circumference of a gas turbine exhaust chamber
Means for issuing an alarm command when there is a defect, a means for issuing a trip command when two or more temperature detectors T adjacent to each other have a defect, and the detection values of the temperature detectors T not adjacent to each other are the first. When the set value of is exceeded, it is also adjacent to each other 2
A means for issuing an alarm command when the detected values of the one or more temperature detectors T exceed the second set value, and a detector adjacent to the detector that exceeds the first set value is the defective detector or the second set value. When the detector exceeds the value or when the detected values of the two detectors that are adjacent to each other across the defective detector exceed either the first set value or the second set value, a trip command is issued. And a means to put it out.

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 monitoring device which plays a role of protecting a gas turbine used for power generation or the like.

[0002]

BACKGROUND OF THE INVENTION Gas turbine combustors typically use a plurality of can-type combustion liners in which fuel is combusted to produce a generally annular hot gas stream for driving the turbine. ..

Since this turbine combustor has extremely high pressure and temperature, even a relatively small defect in the combustor can cause serious damage to the gas turbine if it is overlooked without being noticed.

Therefore, monitoring the temperature of the gas turbine exhaust gas plays an important role in safely operating the gas turbine. In other words, the first role is used to calculate the combustion temperature from the gas turbine exhaust gas temperature and adjust the fuel supply amount of the gas turbine so that the combustion temperature does not rise above the specified value. If it goes up, stop the gas turbine for safety. Also, the second
Is to monitor the combustion state of the combustor. FIG. 6 shows the configuration of a conventional gas turbine combustion monitoring device that plays the second role.

The air compressed by the air compressor 1 is supplied to the combustor 2. Further, fuel is supplied to the combustor 2 via a fuel valve 4. Fuel and compressed air are combusted in the combustor 2 to generate high-temperature gas. This hot gas flow is turbine 3
Is driven to pass through the exhaust chamber 5 and is discharged. Exhaust gas temperature detectors T1 to T3 are installed in the exhaust chamber 5, and temperature detection values obtained from these are input to the gas turbine combustion monitoring device 8. In addition, the gas turbine combustion monitoring device 8 includes an air compression discharge temperature detector 7 installed at the discharge of the air compressor 1.
The detected temperature value obtained from is input. The gas turbine combustion monitoring device 8 outputs a command to the fuel valve 4.

The relationship between the exhaust gas temperature detectors T1 to T13 and the combustor 2 will be described with reference to FIG. 5, which is a schematic view of the gas turbine 3 as viewed from the exhaust chamber direction of the gas turbine. Using a plurality of temperature detectors T1 to T13 installed on the circumference of the gas turbine exhaust casing (there are thirteen temperature detectors in the case shown, but the temperature detectors may vary depending on the size of the gas turbine 3 and the like). The temperature distribution in the circumferential direction of the gas turbine exhaust chamber is measured, and the combustors B1 to B10 (10 combustors in the case shown in the drawing) are also arranged in the circumferential direction. However, the number of combustors differs depending on the size of the gas turbine 3, etc.).

Next, the second role of the gas turbine exhaust gas temperature monitoring will be described in more detail with reference to FIGS. 3 and 4. FIG. 4 is a radar display of the gas turbine exhaust gas temperature distribution, and FIG. 3 is a line display of the gas turbine exhaust gas temperature distribution. For example, when a certain abnormal combustion occurs,
If the temperature detection values obtained by the gas turbine exhaust gas temperature detectors T1 to T13 are as shown in FIG. 3 and FIG. 4, the temperature detection values at this time are not uniform, and within a range where variations occur. It is distributed in. The highest temperature detection value Ths of these is the detection value of the temperature detector T12, the lowest temperature detection value TL1 is the temperature detector T8 detection value, and the second lowest temperature detection value TL2 is
It is the temperature detection value of the temperature detector T7.

Next, detailed functions of the conventional gas turbine combustion monitoring device will be described with reference to FIG. The exhaust gas temperature detection values Tx1 to Tx13 obtained from the gas turbine exhaust gas temperature detectors T1 to T13 are input to the temperature input device 10 in the gas turbine combustion monitoring device 8. The temperature detection values Tx1 to Tx13 input to the temperature input device 10 are rearranged by the sorting device 11 from a high temperature detection value to a low temperature detection value. Further, the temperature detection value T of the temperature input device 10
Based on x1 to Tx13, the average value Txm of the gas turbine exhaust gas temperature is calculated by the average value calculator 12. Further, the temperature detection value Ted obtained from the air compression discharge temperature detector 7 is input to the temperature input device 14 in the gas turbine combustion monitoring device 8. The detected air compressor discharge temperature value Ted is input to the allowable deviation value calculator 16 via the upper and lower limiter 15. In this allowable deviation value calculator 16, from the gas turbine exhaust gas temperature average value Txm from the average calculator 12 and the air compressor discharge temperature Ted from the upper and lower limiter 15 at the same time,
The gas turbine exhaust gas temperature allowable deviation value Tad is calculated by the following equation.

A technique for calculating the allowable deviation value of the gas turbine exhaust gas temperature as a function of the air compressor discharge temperature and the exhaust gas temperature average value is described in JP-B-59-12851. Tad = a * Txm-b * Ted + c Note that a, b, and c are defined constants. Next, the maximum temperature detection value Ths and the minimum temperature detection value Tl1 of the exhaust gas temperature detection values rearranged by the sorting device 11 are arranged.
And the temperature detection value TL2 which is the second lower than the lowest,
The temperature difference calculator 13 calculates the temperature deviation SPRED based on the following formula.
1 and the temperature deviation SPRED2 are calculated. SPRED1 = Ths-TL1 = Tx12-Txs6 SPRED2 = Ths-TL2 = Tx12-Txs7 Then, the logic calculator 17 causes the temperature deviation SPRED.
When 1 exceeds the specified value K1 times the allowable temperature deviation value Tad and a certain specified time 17.1 has passed, an alarm display of "exhaust gas temperature detector abnormality" is displayed on the alarm display 18. The specified value K1 is generally about 5.0.

Further, when the temperature deviation SPRED1 exceeds the specified value K2 times the allowable temperature deviation Tad and does not exceed the specified value K1 times when the specified time 17.2 has elapsed, or the temperature deviation SPRED2 is the allowable temperature deviation SPRED2. If the deviation Tad exceeds the specified value K3 times and the temperature deviation SPRED1 exceeds the allowable temperature deviation Tad specified value K1 times, the specified time 1
When it exceeds 7.3, a fuel cutoff command is output to the fuel valve 4 in order to display an alarm of "combustion abnormal trip" on the alarm display 19 and to trip the gas turbine. The specified value K2 is generally about 1.0, and the specified value K3 is 0.
A value of about 8 is used.

That is, the exhaust gas temperature of the gas turbine is preferably uniform in the circumferential direction of the gas turbine exhaust chamber, which causes abnormal combustion (partial misfire, etc.) of the combustor. Then, the exhaust gas temperature fluctuates, and when this fluctuation exceeds a certain amount, the gas turbine is stopped as a "combustion abnormal trip".

[0012]

However, since a thermocouple is used in the gas turbine exhaust gas temperature detector,
Frequently problems such as disconnection occur. The cause is stress due to rapid temperature change due to frequent start and stop of the gas turbine, microvibration during gas turbine operation, and adverse environment such as oxidation due to exhaust gas. If the exhaust gas temperature detectors T1 to T13 are used, When one of the thermocouples is broken, the output of the broken thermocouple becomes almost zero, so that the temperature deviation SPRED1 instantly becomes large. Then, the temperature deviation SPRED1 exceeds the allowable temperature deviation Tab by K1 times, and an alarm display of "abnormality of exhaust gas temperature detector" is displayed. If the other thermocouple is disconnected in this state, the output of the disconnected thermocouple will be almost zero, so the temperature deviation SPRED2 will instantly increase, and the temperature deviation SPRED2 will exceed K2 times the allowable temperature Tab. I will end up. For this reason, he had to trip the gas turbine. In this way, if the gas turbine trips due to the trouble of the two exhaust gas temperature detectors, stable power supply cannot be expected. The object of the present invention is to operate the gas turbine from the state of the detection position of the defective exhaust gas temperature detector without immediately stopping the gas turbine even if there are two or more defective gas turbine exhaust gas temperature detectors. It is to provide a gas turbine combustion monitoring device that determines whether or not to continue.

[0013]

The gas turbine combustion monitoring apparatus according to the present invention is provided when the temperature detectors which are not adjacent to each other out of a plurality of temperature detectors provided on the circumference of the gas turbine exhaust chamber become defective. Detector abnormality alarm means for issuing an alarm command, detector abnormality trip means for issuing a trip command when two or more temperature detectors adjacent to each other out of a plurality of temperature detectors become defective, and temperature detection not adjacent to each other Abnormality alarm means for issuing an alarm command when the detection value of the detector of the detector exceeds the first set value or when the detection values of two or more temperature detectors adjacent to each other exceed the second set value,
When a detector adjacent to a detector that detects a detection value exceeding the first set value is a defect or a detector that detects a detection value that exceeds the second setting value, or is adjacent to each other across the defect detector. And a combustion abnormality trip means for issuing a trip command when the detection values of both detection devices exceed either the first set value or the second set value.

[0014]

As a result, it is possible to separately output the abnormal case of the gas turbine exhaust gas temperature detector and the abnormal case of the combustion without confusion.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the gas turbine combustion monitoring device according to the present invention will be described with reference to FIG.

Also in the gas turbine combustion monitoring apparatus according to this embodiment, the temperature detection values Tx1 to Tx13 from the exhaust gas temperature detectors T1 to T13 installed in the gas turbine exhaust chamber shown in FIG. The temperature detection value Ted from the air compressor discharge temperature detector installed at the machine discharge is input to the temperature input devices 10, 14 of the gas turbine combustion monitoring device 8. The detected temperature values Tx1 to Tx13 input to the temperature input device 10 are detected by the maximum value selector 20 as the maximum detected temperature value Ths among the detected temperature values Tx1 to Tx13.
Has been selected as. Also, these temperature detection values Tx1
.About.Tx13 is compared with a prescribed value Txy by the defect determiner 21. As the specified value Txf, the lowest value of the exhaust gas temperature in the operating range of the gas turbine when the gas turbine combustion monitoring device is implemented, generally a value of about 200 ° C. is used. The temperature detection value Txn lower than the specified value Txf is determined to be defective in the temperature detector, and is stored in the “defect determination” column of the determination result storage 25. In FIG. 1, an * mark is shown in the column of the temperature detector determined to be defective.

Next, the defect determiner 21 calculates the exhaust gas temperature average value Txm by the average value calculator 22 based on the detected temperature value Txxn which is equal to or higher than the specified value Txf. Temperature input device 14
The detected air compressor discharge temperature value Ted is input to the allowable deviation value calculator 16 via the upper and lower limiter 15. In this allowable deviation value calculator 16, the exhaust gas temperature average value Tx from the average value calculator 22 is the same as that of FIG.
The gas turbine exhaust gas allowable deviation value Tad is calculated from m and the air compressor discharge temperature detection value Ted from the upper and lower limiter 15. Further, the exhaust gas temperature detection values Tx1 to Tx13 input to the temperature input device 10 are compared by the defect determination device 21, and then the SPRED1 determination device 23 performs the following comparison processing.

(Maximum temperature detection value Ths-Temperature detection value Tx
n> allowable deviation value Tab × specified K1) The allowable deviation value Tab × specified value K1 in this case is referred to as a first predetermined value. The specified value K1 is generally about 1.0.
A temperature detector in which the difference between the maximum temperature detection value and the temperature detection value exceeds the first predetermined value is determined to be combustion abnormality detection and is stored in the “SPRED1 determination” column of the determination result storage 25. In FIG. 1, the column of the temperature detector determined to be the combustion abnormality detection by the SPRED1 determiner 23 is marked with *. The temperature detector determined to be defective by the defect determiner 21 is indicated by a # mark in the "SPRED1 determination" column of the determination result storage 25. The temperature detection values Tx1 to Tx13 compared by the SPRED1 determiner 23 are next SPRED2.
The decision unit 24 carries out the following comparison processing.

(Maximum temperature detection value Ths-Temperature detection value Tx
n> allowable deviation value Tab × specified value K2) The allowable deviation value Tab × specified value K2 in this case is referred to as a second predetermined value. or,
This prescribed value K2, generally a value of about 0.8 is used.
A temperature detector whose difference between the maximum temperature detection value and the temperature detection value exceeds the second predetermined value is determined to be combustion abnormality detection and is stored in the "SPRED2 determination" column of the determination result storage 25. In FIG. 1, the column of the temperature detector judged as the combustion abnormality detection by the SPRED2 judging device 24 is marked with *.
The temperature detector determined to be defective by the defect determiner 21 is also indicated by a # mark in the “SPRED2 determination” column of the determination result storage 25. Further, the temperature detector determined to be combustion abnormality detection by the SPRED1 determiner 23 is indicated by an α mark in the “SPRED2 determination” column of the determination result storage 25. Next, the judgment result storage 2
Based on the data in 5, the logic calculator 26 performs the following processing.

1) "Defect determination" in the determination result storage 25
If there is more than one * in the column, the alarm contact Sp1
Is output. 2) When there are two or more consecutive * marks in the "Defect judgment" column in the judgment result storage 25 (this judgment, the temperature detector is T
x1 to Tx2 ... Tx13 to Tx1 to Tx2 are circulated for scanning, so in other words, one or both columns adjacent to the one marked * in the "Defect determination" column have an asterisk (*).
Outputs the trip contact Sp2. 3) If there is one or more consecutive * marks in the "SPRED2 Judgment" column in the judgment result storage 25, the alarm contact S
Output p3. 4) When two or more consecutive "*" marks appear in the "SPRED2 determination" column in the determination result storage 25 ("SPRED2
Adjacent to the column marked with * in the "Judgment" column, in one or both columns *
If there is a mark), the alarm point Sp4 is output. 5) If there is a # mark in one or both columns adjacent to the one marked * column in the "SPRED1 Judgment" column in the judgment result container 25, the trip contact Sp5 is output. 6) When there is an α mark in one or both columns adjacent to the one-marked column in the “SPRED2 determination” column in the determination result container 25, the trip contact Sp6 is output. 7) If there is an α mark in both columns adjacent to the # mark column in the “SPRED2 determination” column in the determination result storage 25, the trip contact Sp7 is output. 8) When the output of Sp1 exceeds the specified time 26.1, the "exhaust gas temperature detector abnormality" alarm indicator 18 is displayed. 9) When the output of Sp2 exceeds the specified time 26.2, "exhaust gas temperature detector abnormal trip" alarm indicator 27
Is displayed. 10) When the output of Sp3 or the output of Sp4 exceeds the specified time 26.3, the "combustion abnormality" alarm display 28 is displayed. 11) When the output of Sp5, the output of Sp6, or the output of Sp7 exceeds the specified time 26.4, the "combustion abnormal trip" alarm indicator 19 is displayed. 12) When the output of Sp2 exceeds the specified time 26.2, the output of Sp3 or the output of Sp4 exceeds the specified time 26.4, the fuel valve 4 is instructed to shut off the fuel. Is output.

That is, in the gas turbine combustion monitoring apparatus according to this embodiment, for example, in FIG. 3, the temperature detector T3 and the temperature detector T13 temporarily have defects such as disconnection, and the temperature detection values Tx3 and Tx13 are almost zero. If this happens, only the functions 1) and 8) of the logic calculator 26 operate and only the "exhaust gas temperature detector abnormality" alarm indicator 18 is displayed, and the gas turbine is not tripped. or,
For example, in FIG. 3, if the temperature detector T3 temporarily fails such as disconnection, the temperature detection value Tx12 of the temperature detector T12 is set as the maximum temperature detection value Ths, and the temperature difference from the temperature detection value Tx8 of the temperature detector T8 is the above-mentioned value. When a value exceeding the predetermined value of 1 occurs, the temperature detector T3 operates the functions of the logic calculator 26 in the items 1) and 8), and outputs an alarm of "exhaust gas temperature detector abnormality" to the alarm indicator 18. The temperature detector T8 causes the alarm indicator 28 to display an alarm "combustion abnormality" due to the functions of the logic calculator 26, items 1) and 8).

[0022]

As described above, according to the present invention, it is possible to easily distinguish between the malfunction of the gas turbine exhaust gas temperature detector and the true combustion abnormality, and the malfunction of the exhaust gas temperature detector. It is possible to prevent easy gas turbine stoppage.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional example.

FIG. 3 is an explanatory diagram of the detected value of exhaust gas temperature.

[Fig. 4] Characteristic diagram of exhaust gas temperature distribution curve

FIG. 5 is an explanatory diagram of a positional relationship between a combustor in a gas turbine exhaust chamber and a temperature detector.

FIG. 6 is an explanatory diagram of a gas turbine combustion monitoring device in a gas turbine plant.

[Explanation of symbols]

 1 Air Compressor 2 Combustor 3 Gas Turbine 4 Combustion Valve 5 Exhaust Chamber 8 Gas Turbine Combustion Monitoring Device 26 Logic Calculator

Claims (1)

[Claims] 1. A gas turbine combustion monitor for monitoring the combustion state of a gas turbine by providing a plurality of temperature detectors on the circumference of a gas turbine exhaust chamber, wherein the temperature detectors that are not adjacent to each other among the plurality of temperature detectors. Detector abnormality alarm means for issuing an alarm command when the temperature of the detector is defective, and a detector abnormality trip for issuing a trip command when two or more temperature detectors adjacent to each other among the plurality of temperature detectors are defective Means and the detection values of the temperature detectors not adjacent to each other are first
When the set value exceeds the set value or when the detected values of two or more temperature detectors adjacent to each other exceed the second set value, the abnormal alarm means for issuing an alarm command and the detected value exceeding the first set value are detected. When the detector adjacent to the detected detector is a defect detector or a detector that has detected a detection value exceeding the second set value, or the detection values of both detectors that are adjacent to each other across the defect detector are A gas turbine combustion monitoring device comprising: a combustion abnormality trip means for issuing a trip command when either the first set value or the second set value is exceeded.