JP2001329856A - Gas turbine, its fatigue diagnostic device, and its fatigue diagnostic method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine and its fatigue diagnostic device capable of evaluating the operating vibration stress of compressor blades with high precision and accurately determining the fatigue life and replacement timing of the compressor blades. SOLUTION: This gas turbine coaxially incorporating a turbine and a compressor in a casing is provided with a pressure sensor 44 measuring the pressure at the turbine stage section of the compressor casing 3, a data collecting device collecting the measured values of the pressure sensor, and a calculating device having a strength master curve under the corrosive environment and a structural analysis model of pressure fluctuations at the turbine stage and the compressor blades. The calculating device performs the stress analysis of the compressor blades from the strength master curve and the structural analysis model, analyzes fatigue damage, and determines the replacement timing of the blades.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine, a device for diagnosing fatigue thereof, and a method of diagnosing fatigue thereof.

[0002]

2. Description of the Related Art A conventional gas turbine of this type is provided with a compressor for compressing air and sending the compressed air to a combustor. Inside the compressor, a central shaft of the gas turbine is provided. A compressor rotor is provided that rotates about and has compressor blades embedded in a disk. Needless to say, compressor vanes for rectifying air are embedded in the rotor rotor blades also on the side of the compressor casing that houses the compressor rotor.

[0003] Since this type of compressor sucks and compresses the atmosphere, dust tends to adhere to the above-mentioned compressor blades.
If dust (substance) having a corrosive action adheres to the blades, not only the efficiency of the compressor is reduced, but also corrosion pits may be generated and the fatigue life may be shortened.

In general, a corrosive substance adhering to a compressor blade is periodically removed to extend the life of the compressor blade, and the fatigue life of the compressor blade is empirically predicted.
The compressor blades are replaced at predetermined intervals. Various ideas are used to predict and determine the life extension measures, fatigue life, and replacement time of the compressor blades, and a life extension method or a judgment method that seems to be optimal depending on the surrounding environment and operating conditions where the equipment is installed is adopted. ing.

[0005] As a method of extending the life of a compressor blade, for example, the fatigue life with respect to a fluid excitation load applied when the compressor compresses air can be extended by adding a compressive residual stress to the compressor. As disclosed in JP-296453-A, cleaning water is injected from a compressor suction port of a gas turbine, drainage after cleaning is discharged from a drainage drain to remove dirt from the compressor, and extend the life of the compressor blades. Some do so.

That is, in general, a gas turbine has an open-to-atmosphere cycle. When sucking air during operation, a dust removal filter provided at an intake portion cannot remove fine dust in the atmosphere, and a compressor is not used. Wash water is injected into the compressor blades from a water cleaning device provided in the air intake, and the compressor efficiency is restored by removing dirt from the blades.

[0007]

As described above, dust that cannot be removed by a filter from the compressor suction port adheres to the compressor blades. If the corrosive substances such as sodium and potassium contained in seawater or sulfur dioxide gas and nitrogen oxide contained in atmospheric soot adhere to the wings, the wings are put in a corrosive environment. As a result, corrosion pits are generated and the fatigue life is shortened. Further, it is known that, in a salt water environment or an acid solution environment, the fatigue strength of 12Cr steel or the like generally used for a compressor blade material is reduced. For such an example, see, for example, the Allianz Damage Prevention Handbook (published by Japan Machinery Insurance Federation, March 1991).
1) on pages 379 to 380.

The compressor blades are subjected to a gas reaction force for compressing air during operation of the gas turbine, and a vibration load due to pressure fluctuation. Compressor blades are designed so that the stress generated under these loads is less than the design allowable stress considering a certain safety factor against the fatigue limit of the material. However, as described above, in a corrosive environment, the fatigue limit of the material decreases, so the safety factor against the design load decreases,
In some cases, it is assumed that the reliability of the wing cannot be guaranteed. In addition, it is assumed that the reliability of the blade cannot be guaranteed even with the progress of the corrosive environment due to the deterioration of the atmospheric environment that cannot be considered at the time of design.

At this time, in order to guarantee the reliability of the wing,
It is necessary to accurately estimate the actual vibration stress generated on the blade and the corrosive environment to which the blade is exposed, and to evaluate the strength and the remaining life, but in the above-mentioned conventional type, the actual vibration stress of the blade and the actual corrosive environment It is difficult to evaluate the water content accurately, and the corrosive environment can be improved by frequently performing water washing as disclosed in JP-A-8-296453. However, water washing generally needs to be performed when the gas turbine is stopped. Frequently, this is difficult from an operational and economic point of view.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and an object of the present invention is to accurately evaluate the actual vibration stress of a compressor blade and accurately determine the fatigue life and replacement time of the compressor blade. It is an object of the present invention to provide a gas turbine of this kind and a fatigue diagnosis device and a fatigue diagnosis method thereof. Another object is to provide a gas turbine that can extend the life of a compressor blade.

[0011]

That is, the present invention relates to a method for diagnosing fatigue of a blade provided in a gas turbine compressor, the method for diagnosing fatigue of a blade of a gas turbine. Then, a stress analysis is performed using the measured pressure fluctuation data and a predetermined structural analysis model of the compressor blade to estimate the stress fluctuation in the actual operating environment of the compressor blade. Comparing the stress fluctuation with the strength master curve of a predetermined compressor blade material in a corrosive environment, evaluate the fatigue damage of the compressor blade, and determine the replacement time of the compressor blade based on the evaluated fatigue damage In order to achieve the intended purpose.

Further, the present invention provides a gas turbine fatigue diagnosis device provided in a gas turbine compressor for diagnosing blade fatigue, comprising: a pressure measuring means for measuring a pressure in a paragraph section of the gas turbine compressor; A data collection device that collects the measured values of the pressure measurement device, and performs a stress analysis using the pressure fluctuation data of the data collection device and a predetermined structural analysis model of the compressor blade, and in a working environment of the compressor blade. Estimate the stress fluctuation, compare the estimated stress fluctuation of the compressor blade with the strength master curve under the corrosive environment of the predetermined compressor blade material, and evaluation means to evaluate the fatigue damage of the compressor blade. And means for determining the replacement time of the compressor blade based on the evaluated fatigue damage.

Further, in a gas turbine in which a turbine and a compressor are coaxially contained in a casing, a pressure sensor for measuring a pressure in a stage portion of the compressor casing, A data collection device for collecting values, a strength master curve in a corrosive environment, and a calculation device having a structural analysis model of pressure fluctuations in the paragraphs and the compressor blades. Stress analysis of compressor blades is performed using a structural analysis model, fatigue damage is analyzed, and the time for blade replacement is determined.

Further, a gas turbine compressor in which a turbine and a compressor are coaxially contained in a casing, washing water is injected from an air suction port of the compressor, and is discharged after washing to remove dirt from the compressor. In a gas turbine provided with a water washing device, a detection unit for detecting the pH of the discharged washing water, a pressure sensor for measuring a pressure in a paragraph portion of the compressor casing, and a measurement of the pressure sensor. A data collection device for collecting values, and a calculation device having a structural analysis model of a pressure master in a corrosive environment, a pressure fluctuation in a paragraph, and a compressor blade. A compressor blade is subjected to stress analysis based on a structural analysis model and the pH data of the washing water to analyze fatigue damage and determine a blade replacement time. It is.

Further, a gas turbine compressor in which a turbine and a compressor are coaxially contained in a casing, and washing water is injected from an air suction port of the compressor, and is discharged after washing to remove dirt from the compressor. In a gas turbine provided with a water washing device, the gas turbine is provided with a drainage sampling mechanism for the discharged washing water, a pressure sensor for measuring a pressure in a paragraph portion of the compressor casing, and a measurement value of the pressure sensor. A data collection device to be collected, and a calculation device having a strength master curve in a corrosive environment, a structural analysis model of pressure fluctuation of a paragraph and a compressor blade, and the calculation device includes the strength master curve and the structural analysis. Compressor blade stress analysis based on the model and the drainage sample data, fatigue damage analysis, and determination of blade replacement time A.

According to another aspect of the present invention, in a gas turbine in which a turbine and a compressor are coaxially contained in a casing, a temperature sensor for measuring a temperature in the compressor casing is provided to the gas turbine; Sensor for measuring the humidity of the air to be heated, a mechanism for flowing dry air through the casing based on the measurement data of the temperature sensor and the humidity sensor, a pressure sensor for measuring the pressure in the paragraph section of the compressor casing, and the pressure sensor A data collection device for collecting the measured values of the temperature, and a calculation device having a structural analysis model of the strength master curve in the corrosive environment, the pressure fluctuation of the paragraph and the compressor blade, and the measurement of the temperature measurement sensor and the humidity sensor The dry air is allowed to flow through the casing according to the data, and the intensity master curve is calculated by the calculation device. Preliminary structural analysis model performs a stress analysis of the compressor blades, to analyze the fatigue damage, is obtained so as to determine the time to replace the wing.

That is, according to the gas turbine formed as described above, the gas turbine includes a pressure sensor for measuring a pressure in a paragraph portion of the compressor casing, a data collection device for collecting a measured value of the pressure sensor, and a gas turbine. A calculation device having a structural analysis model of the strength master curve under the environment, the pressure fluctuation of the paragraph, and the compressor blade is provided, and the calculation device uses the strength master curve and the structural analysis model to calculate the compressor blade. Since stress analysis and fatigue damage analysis are performed to determine the blade replacement time, the actual operating vibration stress of the compressor blade can be accurately evaluated, and the compressor blade fatigue life and replacement time are accurately determined. You can do it.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows the gas turbine equipment. 1 is a gas turbine main body, 2a is a compressor, 14a is a turbine, 15 is a combustor, and 18 is a compressor air suction port.

The rotor 2 of the compressor is formed by implanting a compressor rotor blade 7 into the rotor shaft via a dovetail.
The rotor shaft is formed by connecting a compressor stub shaft 4 and a compressor disk 5 with compressor stacking bolts 6. The compressor casing 3 includes a compressor vane 8 therein, and the compressor vane 8 is formed by being fitted into a groove provided in an inner wall of the compressor casing, and is sucked through a compressor air suction port 18. It is responsible for rectifying the air and sending it to the compressor rotor blades 7.

The turbine rotor 9 has a turbine stub shaft 10, a turbine disk 11, and a distance piece 12 connected by stacking bolts 13, and turbine blades 14 are planted on the rotor. During operation of the gas turbine, this rotor rotates, air is sucked in from the arrow A, compressed by the compressor rotor 2 and sent to the combustor 15.

In the combustor 15, fuel is burned, and the generated combustion gas is rectified by the turbine nozzle 16, rotates the turbine rotor 9, and rotational energy used for power generation and the like is extracted from the rotor. The gas turbine 1 is fixed on a turbine base 17.

In this embodiment, the compressor casing 3
, A pressure sensor (pressure measuring means) 44 is attached.
The pressure fluctuation data of the compressed air measured by the pressure sensor 44 is sent to the recording device 29 via the sensor amplifier 45 and the signal line 38.

FIG. 2 shows an enlarged manner of mounting the pressure sensor 44. In this example, a pressure sensor mounting hole is formed in the compressor casing 3, and the pressure sensor 44 is mounted in this hole. In addition,
The pressure sensor may be a commonly used one, for example, a strain gauge type pressure sensor. As shown in this figure, by attaching the pressure sensor 44 to each paragraph of the compressor casing 3, the pressure fluctuation of the compressed air at the position of the stationary blade 8 sandwiched between the pressure sensors 44, that is, the pressure of the paragraph Variation is measured.

Returning to FIG. 1, the pressure is measured by the pressure sensor 44,
The pressure fluctuation data recorded in the recording device 29 is
The data is stored in the data recording device 31 using “0”. The data recording device 31 holds a stress analysis model of a compressor blade. Then, the computer 30 reads the above-mentioned pressure fluctuation data and the stress analysis model of the compressor blade, and calculates response stress due to the pressure fluctuation of the compressor blade using the pressure fluctuation data and the stress analysis model of the compressor blade.

Then, by comparing the calculated stress waveform of the compressor blade with the material strength data under the environment,
Calculate wing fatigue damage. The evaluated fatigue damage is collected and recorded in a data recording device. As a result, the accumulated fatigue damage of the blade can be accurately and promptly evaluated, the replacement time of the compressor blade can be determined based on the accumulated fatigue damage, and the reliability of the gas turbine can be improved.

FIG. 3 shows a system configuration diagram of the remaining life evaluation of the compressor blade in one embodiment of the present invention. The system for evaluating the remaining life of the compressor blade includes a data input / output control subsystem 47, a vibration analysis subsystem 48, a fatigue damage analysis subsystem 49, a waveform analysis subsystem 50, a remaining life evaluation subsystem 51, and a database 52. It is configured. The arrows in the figure indicate the flow of data between the devices.

The remaining life evaluation step will be described with reference to FIG. 3. The data input / output control subsystem 47 controls input / output of data used in the present invention. The vibration analysis subsystem 48 performs a blade vibration analysis using the finite element method analysis model of the compressor blade stored in the database 52, the damping ratio data of the compressor blade, and the pressure fluctuation data.
Predict stress fluctuations in the operating environment of compressor blades. In this case, the vibration analysis may use a time history response analysis for analyzing a time history waveform of a response of the structure, or may use a frequency response analysis for obtaining a steady-state response. When the time history waveform of the fluctuating stress is obtained by the time history response analysis, the result of the stress waveform analysis is recorded in the database 52.

FIG. 4 (b) shows an example of the pressure fluctuation used in the vibration analysis, in which the compressor blade generates the largest vibration stress during its operation. The waveform at the time is shown. Swirling stall is a pressure fluctuation phenomenon peculiar to a compressor. The compressor rotor blades and the stationary blades are excited, and a higher vibration stress is generated in these blades as compared with a normal operation.

FIG. 5 shows the result of measuring the stress by attaching a strain gauge to the compressor stationary blade. As is apparent from the measurement results, turning stall occurs when the rotation speed is around 70% of the rated rotation speed, and the blade stress increases. The stress at the time of the rotating stall of the blade is a main factor of the fatigue damage, and by determining this stress with high accuracy, the fatigue damage of the blade can be obtained with high accuracy.

FIG. 6 shows a turning stall mechanism. Swirling stall is a phenomenon in which a separation area occurs on a blade and a stall cell whose flow is blocked is rotated while the compressor is operating at a speed other than the rated operation. The wing is excited by passing through the stall cell. The excitation frequency of the wing is represented by the following equation, and the coefficient a is known to be about 0.5.

[0031]

Fs = n · a · frps · j (1) where fs is the blade excitation frequency, n is the number of stall cells,
a is a coefficient, and frps is a rotation frequency of the rotor. In addition,
j is an integer.

In the pressure fluctuation waveform shown in FIG. 4B, the number of the rotating stall cells is 1 (n = 1). FIG.
(A) shows a rotation pulse of the rotor, and shows a time required for one rotation of a peak interval. From this figure,
It can be seen that there is one pressure fluctuation waveform between two rotations of the rotor.

FIG. 7 shows a spectrum obtained by frequency analysis of the pressure fluctuation waveform. The frequency analysis of the pressure fluctuation waveform is performed by the waveform analysis subsystem 50. Thus, it can be seen that the pressure waveform at the time of the rotating stall is represented by a multiple wave j = 1, 2, 3, 4... Of the fundamental wave of n = 1 represented by the expression 1 of the rotational speed. FIG. 7 shows the change of the spectrum of the fluctuating stress waveform for each rotation speed and the natural frequency of the compressor blade. According to this figure,
It can be seen that the rotating stall waveform increases when the rotation speed is around 70% of the rated rotation speed, and that the fifth harmonic of the fundamental wave approaches the natural frequency of the blade. For this reason, as shown in FIG. 5, when the rotation speed is around 70% of the rated rotation speed, the blade stress increases.

FIG. 8 shows a mechanism in which the pressure waveform at the time of the rotating stall has a spectrum in which the frequency is expressed by the equation. The fluctuating pressure waveform close to the trapezoid in FIG. 4B was modeled by simplifying it to the waveform shown in FIG. When the waveform of FIG. 8 is Fourier-expanded, it can be seen that the waveform is expanded into integer multiples j = 1, 2, 3, 4...

The vibration stress waveform of the compressor blade can be obtained by adding the pressure fluctuation waveform shown in FIG. 4B to the finite element method analysis model of the compressor blade and performing a time history response analysis. FIG. 9 shows a stress analysis model. The pressure fluctuation waveform may be uniformly applied to the blade surface, or the pressure distribution on the blade surface may be CFD.
If it is evident from measurements or actual measurements, it may be added with a distribution. When performing vibration analysis, if the database 52 stores the data of the natural frequency of the compressor and the result of measuring the actual dynamic stress of the blade, the analysis model is corrected. In the modification of the analysis model, the constraints and attenuation of the model are changed.

In the case of calculating stress by frequency response analysis, as shown in FIGS. 7 and 8, the pressure fluctuation of the rotating stall utilizes the characteristic that the harmonic wave is a superposition of the fundamental wave. That is, the amplitude of the peak having the frequency of the harmonic of the fundamental wave shown in FIGS. 7 and 8 is added to the frequency response analysis model.

By taking into account a plurality of predominant peak pressure fluctuations, the blade stress amplitude can be accurately determined. FIG. 10 compares stress analysis results with test results when considering multiple peaks and when considering only a single peak near the natural frequency of the blade. According to this, it is understood that the stress at the time of turning stall is accurately obtained on the safe side by considering a plurality of peaks.

When obtaining a time history waveform of stress by frequency response analysis in consideration of a plurality of pressure fluctuation peaks shown in FIG. 10, a time history of a sine wave having each pressure peak obtained by the frequency response analysis is used. Waveforms are generated, and these are added to obtain a time history waveform of stress. As shown in FIG. 8, the pressure waveform of the rotating stall is a sum of harmonics of the fundamental wave without a phase difference, so that this method can be easily applied. As shown in FIG. 11A, a phase difference may be provided from the relationship between the frequency of pressure fluctuation and the eigenvalue of the blade using a response curve of a one-degree-of-freedom system. Note that, as the stress analysis model, a stress analysis model that obtains a stress variation from a pressure variation by beam calculation or the like may be used in addition to the finite element method analysis model.

The fatigue damage analysis program 49 reads the above-described stress waveform analysis results stored in the database 52, the actual corrosion environment data of the blade, and the time strength data under the corrosion environment of the blade material, and performs the stress frequency analysis and the cumulative fatigue damage. Perform analysis. As the stress frequency analysis method, rain flow method,
The range pair method, the range pair mean method, the peak method, and the like are generally used to analyze the amplitude and frequency of the fluctuating stress.

In the cumulative fatigue damage analysis, using the stress amplitude, the stress frequency, the actual corrosion environment data of the blade, and the time strength data under the corrosion environment of the blade material obtained by the stress frequency analysis described above, Perform cumulative fatigue damage analysis based on the modified minor rule and calculate the cumulative damage of the wing. The cumulative damage analysis result obtained by the analysis is held in the database 52. Then, the accumulated fatigue damage calculated for each operation is added and stored in the database 52. The time intensity diagram used for the cumulative damage refers to the data of the actual corrosion environment of the compressor blade, and uses the time intensity diagram corresponding to the corrosion environment of the blade. The actual corrosion environment of the blade can be determined by analyzing the cleaning liquid used when cleaning the blade. Note that a crack growth analysis using fracture mechanics may be used instead of the cumulative damage analysis.

In the remaining life evaluation subsystem 51,
Using the cumulative damage analysis result data stored in the database 52 and the limit value of the cumulative damage rate, the allowable number of times of starting and stopping can be calculated. With the program configuration described above, the accumulated fatigue damage of the wing can be accurately and quickly evaluated,
The replacement time of the compressor blade can be determined based on the accumulated fatigue damage, and the reliability of the gas turbine can be improved.

FIG. 12 shows another embodiment. Although the configuration is substantially the same as that of the invention shown in FIG. 1, a thermocouple 46 is attached to the compressor casing 3 in this embodiment. As shown in FIG. 2, the thermocouple 46 has a thermocouple mounting hole formed in the compressor casing 3,
A thermocouple 46 is attached to the hole. The temperature of the inner surface of the casing 3 can be measured by the thermocouple 46. When the gas turbine is stopped, the temperature of the inner surface of the casing measured by the thermocouple 46 and the temperature of the compressor blade embedded in the casing can be considered to be substantially equal. The metal temperature of the wing can be predicted. The measured temperature fluctuation data is sent to the recording device 29 via the sensor amplifier 45 and the signal line 38.

In the present invention, there is provided a mechanism for flowing dry air including the dry air generator 52, the dry air pipe 53 and the valve 54 into the casing 3. The dry air generator 52 and the valve 54 are connected to the computer 30 and the controller 29.
Is controlled by a control signal transmitted through the signal line 38 from The dry air pipe 38 is connected to the position of the bleeding port of the casing 3, an air intake port, and the like, and is provided to guide dry air into the casing 3. As the dry air generating device, a device for exchanging humidity using a rotating channel type absorber is generally used.

According to the present invention, there is provided a device for measuring the relative humidity of the outside air and the outside air temperature of the casing 3 comprising the humidity sensor 55, the temperature sensor 57 and the sensor amplifier 56.
The measured relative humidity data of the air and the outside air temperature data are sent to the control / recording device 29 via the signal line 38. The humidity sensor 55 and the temperature sensor 57 are installed in the same place, and when the gas turbine is stopped, such as in the compressed air suction port 18 or the enclosure containing the gas turbine for measuring the humidity and temperature of the suction air of the gas turbine. It may be installed so as to measure the humidity and temperature of the air that may flow in when it is present. Even when the gas turbine is stopped, outside air flows in from the opening of the casing,
It measures the humidity and temperature of the air that may enter.

The control steps of the present invention will be described with reference to FIG. When the gas turbine is stopped, the data of the outside air humidity sensor 55 and outside air temperature sensor 57
To obtain the saturated steam temperature to of the outside air. The temperature ti on the inner surface of the casing is measured by a thermocouple 46 attached to the casing 3. Then, when to / ti> b, the computer 30 activates the dry air generator 52 via the controller 29. b is a limit value, and it is considered that when b = 1, water vapor contained in air in the compressor condenses on the blade surface of the compressor. b is set to 1 or less in consideration of a safety coefficient. In the present invention, dry air is supplied so that outside air of to> ti does not flow through the casing. Therefore, ti-to <C (C is an integer of 0 or more)
Then, dry air may be circulated.

Next, the computer 30 opens the valve 54 via the control device 29 and guides the dry air into the casing 3 via the dry air pipe 53. According to the present invention, the dew point of the air in the gas turbine casing can be made equal to or lower than the metal temperature of the compressor blade. As a result, condensation of water on the compressor blade surface can be prevented, and a corrosive environment can be improved, so that the reliability of the compressor blade can be improved. Similarly, the relative humidity of the air in the casing 3 may be predicted, and when the relative humidity falls below a certain limit value, the dry air may be circulated through the casing. The limit value of the relative humidity is 50% or less.

The invention shown in FIG. 13 is another embodiment. The configuration is almost the same as that of the invention shown in FIG. In the present invention, the compressor suction port 18 is provided with a gas turbine compressor water cleaning nozzle 19 for injecting cleaning water to remove dirt from the compressor. Generally, a plurality of water washing nozzles 19 are attached to the compressor air suction port 18 at equal intervals in the circumferential direction. The water cleaning nozzle 19 includes a valve 20, a flow meter 21, a pressurized pure water tank 25, a pressurized cleaning liquid tank 26 such as a surfactant, and a pressurized petroleum-based cleaning liquid tank 27 through valves 22, 23, and 24, respectively. Through,
They are connected by pipes.

In this embodiment, the valves 20, 22, 2
The opening and closing of the switches 3 and 24 are controlled by a controller 29 via a signal line 28. For example, opening valve 22 and opening valve 2
By closing the valves 3 and 24 and opening the valve 20, pure water is discharged from the water washing nozzle 19, and the compressor blade can be washed with the pure water. Similarly, the cleaning liquid tank 26,
Cleaning of the cleaning liquid tank 27 with the cleaning liquid is also possible. Further, the amount of the discharged cleaning liquid is measured by the flow meter 21 and the control device 29.
, And the amount of the supplied washing liquid is recorded in the computer 30. With these devices, the compressor blades 7 and 8 are cleaned, and the dirt on the blades is cleaned, thereby restoring the performance of the compressor.

At the lower part of the compressor casing 3, a drain 32 for discharging the washing water after washing and a valve 33 for opening and closing the drain are provided. Drainage by valve 37
It is stored in the sample collecting mechanism 35. The acidity of the wastewater stored in the sample collection mechanism 35 is measured by a pH measuring device 36 that measures the hydrogen ion concentration and measures the acidity of the wastewater. The pH of the washing water is measured by the pH measuring device
By measuring, the corrosive environment to which the compressor blades are actually exposed can be measured. It should be noted that the input pure water amount, the discharged water amount and pH, and the pH of the working environment of the actual wing
By creating the master curve of the relationship, the prediction accuracy of the blade corrosive environment in the present invention can be improved. Also, similarly to the above-described embodiment, by performing a stress analysis using the pressure fluctuation data and the structural analysis model of the compressor blade,
It is possible to estimate the stress fluctuation in the operating environment of the compressor blade. As a result, highly accurate prediction of blade fatigue life can be made by comparing the collected pH data, the strength master curve in a corrosive environment, and the stress fluctuation in a compressor blade in an actual operating environment. Thus, the fatigue life of the blade can be accurately and quickly predicted, and the reliability of the gas turbine can be improved.

The control of the opening and closing of the valve 34, the acquisition of data of the flow meter 36, the control of the pH measuring mechanism 36, and the acquisition of data are performed by the control device 29 via a signal line 38. In the present embodiment, the control of the pH measurement mechanism including the recording, display, opening and closing of valves, control of the pH measurement mechanism including sample collection, control of the water washing mechanism, and recording of the amount of the jet washing liquid are performed by the computer Do with. The present embodiment also includes a recording device 31 for recording measurement data and storing life data of a corrosive environment.

In the embodiment of FIG. 14, the aforementioned FIG.
Unlike the embodiment of FIG. 3, the washing waste water is supplied to the sample collecting device 3.
5 and analyze the collected sample off-line. According to this embodiment, it is possible to analyze the washing wastewater off-line, so that it is possible to perform a detailed analysis at a laboratory level. Examples of the analysis contents include pH analysis, electric conductivity analysis, chromatography, EDX, various elemental analyses, and chemical analysis. According to these analyses, it is possible to evaluate the corrosive environment under the working environment of the compressor blade.

FIG. 15 has substantially the same configuration as the invention shown in FIG. 13 is different from FIG. 13 in that the remote computer 30 and the recording device 31 are connected via an Internet line. As a result, the computer 31 and the recording device 31 that exist in a remote place with higher performance than the computer of the power generation facility
Can be analyzed using As a result, the blade remaining life can be more accurately evaluated, and the reliability of the gas turbine can be improved.

As described above, with the gas turbine formed as described above, for example, the vibration stress and the corrosive environment state during the rotating stall of the compressor stationary blade can be accurately evaluated. Since the remaining life evaluation is performed based on the environment, highly accurate remaining life evaluation can be performed, and the reliability of the gas turbine can be improved. Furthermore, when the gas turbine is stopped, the temperature inside the casing is measured by the temperature sensor inside the casing, and the relative humidity inside the casing is calculated by the temperature sensor and the humidity sensor of the outside air. When the following conditions are satisfied, the dry air is circulated in the casing by a mechanism for circulating the dry air, whereby the dew point of the air in the casing can be lowered, and the condensation of moisture on the wing surface can be prevented. The corrosive environment can be improved.

[0054]

As described above, according to the present invention, the actual vibration stress of the compressor blade is accurately evaluated, and the fatigue life and replacement time of the compressor blade can be accurately determined. A kind of gas turbine and its diagnostic device can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing one embodiment of a gas turbine of the present invention.

FIG. 2 is a sectional view of a gas turbine showing a main part of the gas turbine of the present invention.

FIG. 3 is a program configuration diagram of the first embodiment of the present invention.

FIG. 4 shows fluctuating pressure data in the first embodiment of the present invention.

FIG. 5 is generated stress data of a compressor blade for explaining a first embodiment of the present invention.

FIG. 6 is an explanatory view of turning stall.

FIG. 7 is an explanatory diagram of blade stress generation due to turning stall explaining the first embodiment of the present invention.

FIG. 8 is an explanatory diagram of a frequency characteristic of a pressure fluctuation due to a turning stall, explaining the first embodiment of the present invention.

FIG. 9 is a stress prediction model showing the first embodiment of the present invention.

FIG. 10 is a stress prediction result showing the first example of the present invention.

FIG. 11 is an explanatory diagram of stress prediction showing the first embodiment of the present invention.

FIG. 12 is a sectional view of a gas turbine showing another embodiment of the present invention.

FIG. 13 is a sectional view of a gas turbine showing another embodiment of the present invention.

FIG. 14 is a gas turbine sectional view showing another embodiment of the present invention.

FIG. 15 is a gas turbine sectional view showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas turbine, 2 ... Compressor rotor, 3 ... Compressor casing, 4 ... Compressor stub shaft, 5 ... Compressor disk, 6 ... Stacking bolt, 7 ... Compressor rotor blade, 8 ... Compressor stationary blade, 9 ... Turbine Rotor, 10: turbine stub shaft, 11: turbine disk, 12
... distance pieces, 13 ... stacking bolts, 1
4 Turbine blade, 15 Combustor, 16 Turbine stationary blade, 17 Turbine base, 18 Compressor air suction port, 19 Water washing nozzle, 20 Valve, 21 Flow meter, 2
2 ... valve, 23 ... valve, 24 ... valve, 25 ... pure water tank, 26
... Cleaning liquid (surfactant) tank, 27 ... Cleaning liquid (petroleum) tank, 28 ... Signal line, 29 ... Control / recording device, 3
0: Computer, 31: Data recording device, 32: Drainage drain, 33: Valve, 34: Flow meter, 35: Sample collecting device, 36: pH measuring device, 37: Valve, 38: Signal line, 3
9 Internet line, 44 Pressure sensor, 45 Sensor amplifier, 46 Thermocouple, 47 Data input / output control subsystem, 48 Vibration analysis subsystem, 49 Fatigue damage analysis subsystem, 50 Waveform analysis subsystem ,
51: database, 52: dry air generator, 53
... dry air piping, 54 ... valve, 55 ... humidity sensor, 5
6: sensor amplifier, 57: temperature sensor.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Ken Kudo 3-1-1 Sachimachi, Hitachi-shi, Ibaraki F-term within the Thermal and Hydropower Division, Hitachi, Ltd. F-term (reference) 3H022 AA03 BA04 CA50 DA00 DA09 DA16

Claims (7)

[Claims] 1. A gas turbine fatigue diagnosis method for diagnosing blade fatigue provided in a gas turbine compressor, comprising: measuring a pressure variation of a blade stage of the gas turbine compressor;
A stress analysis is performed using the measured pressure fluctuation data and a predetermined structural analysis model of the compressor blade to estimate a stress fluctuation in the actual operating environment of the compressor blade. Compared with the strength master curve of a predetermined compressor blade material in a corrosive environment, evaluate the compressor blade fatigue damage, and determine when to replace the compressor blade based on the evaluated fatigue damage. A method for diagnosing fatigue of a gas turbine, characterized in that: 2. A gas turbine fatigue diagnostic device provided in a gas turbine compressor for diagnosing blade fatigue, comprising: a pressure measuring means for measuring a pressure in a stage portion of the gas turbine compressor; and the pressure measuring device. A data collection device that collects the measured values of the above, a stress analysis is performed using the pressure fluctuation data of the data collection device and a structural analysis model of a predetermined compressor blade, and the stress fluctuation in the actual operating environment of the compressor blade. And an evaluation means for evaluating the compressor blade fatigue damage by comparing the estimated compressor blade stress fluctuation with a predetermined strength master curve in a corrosive environment of the compressor blade material. Means for determining a replacement time of the compressor blade based on the fatigue damage obtained. 3. A gas turbine in which a turbine and a compressor are coaxially contained in a casing, wherein the gas turbine has a pressure sensor for measuring a pressure in a stage portion of the compressor casing, and a measurement by the pressure sensor. A data collection device for collecting values, a strength master curve in a corrosive environment, and a calculation device having a structural analysis model of pressure fluctuations in the paragraphs and the compressor blades. A gas turbine characterized by performing stress analysis of a compressor blade using a structural analysis model, analyzing fatigue damage, and determining when to replace the blade. 4. A gas turbine compressor in which a turbine and a compressor are coaxially contained in a casing, and washing water is injected from an air suction port of the compressor, and is discharged after washing to remove dirt from the compressor. In a gas turbine provided with a water washing device, detecting means for detecting the pH of the discharged washing water, a pressure sensor for measuring a pressure in a paragraph portion of the compressor casing, and measurement of the pressure sensor in the gas turbine A data collection device for collecting values, and a calculation device having a structural analysis model of a pressure master in a corrosive environment, a pressure fluctuation in a paragraph, and a compressor blade. Stress analysis of the compressor blades was performed based on the structural analysis model and the pH data of the washing water, fatigue damage was analyzed, and the time for blade replacement was determined. Gas turbine with. 5. A gas turbine compressor in which a turbine and a compressor are coaxially contained in a casing, and washing water is injected from an air suction port of the compressor, and is discharged after washing to remove dirt from the compressor. In a gas turbine provided with a water washing device, the gas turbine is provided with a drainage sampling mechanism for the discharged washing water, a pressure sensor that measures a pressure in a paragraph section of the compressor casing, and a measurement value of the pressure sensor. A data collection device to be collected, and a calculation device having a strength master curve in a corrosive environment, a structural analysis model of pressure fluctuation of a paragraph and a compressor blade, and the calculation device includes the strength master curve and the structural analysis. Stress analysis of the compressor blades is performed based on the model and the drainage sample data, fatigue damage is analyzed, and the blade replacement time is determined. Gas turbine. 6. A gas turbine in which a turbine and a compressor are coaxially contained in a casing, a temperature sensor for measuring a temperature in the compressor casing, and a humidity of intake air of the compressor. Humidity sensor, a mechanism for circulating dry air in the casing by the measurement data of the temperature sensor and the humidity sensor, a pressure sensor for measuring the pressure in the paragraph section of the compressor casing, and a measurement value of the pressure sensor. A data collection device to collect, and a calculation device having a structural analysis model of the strength master curve in a corrosive environment, pressure fluctuation of a paragraph, and a compressor blade, are provided in a casing by measurement data of the temperature sensor and the humidity sensor. While allowing dry air to flow, the calculation device uses the strength master curve and the structural analysis model. Perform stress analysis of the compressor blades, analyzing the fatigue damage, gas turbine, characterized in that so as to determine the replacement timing of the wing. 7. A turbine, a compressor, a combustor for mixing fuel and air discharged from the compressor and supplying the fuel gas to the turbine, and a casing containing the turbine and the compressor. In the gas turbine, a temperature measurement sensor mounted in the casing, a temperature sensor and a humidity sensor of the intake air of the compressor, a data collection device, a computer, a recording device, and a mechanism for flowing dry air through the casing are provided. And gas turbine.