JP4459943B2 - gas turbine - Google Patents

Description

  The present invention relates to a gas turbine.

  A gas turbine of this type that has been generally used in the past is provided with a compressor for compressing air and sending it to a combustor. Inside the compressor, the compressor rotates around the central axis of the gas turbine, A compressor rotor in which compressor blades are embedded in a disk is provided. Of course, a compressor vane for rectifying air is also embedded in the rotor blades on the compressor casing side in which the compressor rotor is housed.

  Since this type of compressor sucks and compresses the atmosphere, dust tends to adhere to the compressor blades described above, and if dust (substance) with corrosive action adheres to the blades, the compressor efficiency will decrease. Of course, corrosion pits may occur and the fatigue life may be shortened.

  In general, the corrosive substances adhering to the compressor blades are periodically removed to extend their life, and the fatigue life of the compressor blades is predicted empirically, and the compressor blades are To replace. Various ideas are used to predict and determine the life span of the compressor blades, fatigue life, and replacement time, and the life extension method or judgment method that is considered to be optimal depending on the ambient environment and operating conditions in which the equipment is installed is adopted. ing.

  As a method for extending the life of the compressor blades, for example, the fatigue life against a fluid excitation load that is applied when the compressor compresses air is extended by adding a compressive residual stress, or disclosed in Patent Document 1. As shown in the figure, cleaning water is jetted from the compressor suction port of the gas turbine, and the waste water after cleaning is discharged from the drainage drain to remove the dirt from the compressor, thereby extending the life of the compressor blades. .

  In other words, gas turbines generally have an open air cycle, and when the air is sucked in during operation, the dust removal filter provided in the intake section cannot remove fine dust in the air, and the compressor air intake port. The washing water is sprayed from the water washing device provided in the compressor onto the compressor blades, and the compressor efficiency is recovered by removing dirt from the blades.

JP-A-8-296453

  As described above, dust that cannot be removed by the filter from the compressor suction port adheres to the compressor blades. Among these deposits, if corrosive substances such as sodium and potassium contained in seawater or sulfurous acid gas and nitrogen oxide contained in soot in the atmosphere adhere to the blade, the blade is placed in a corrosive environment. Corrosion pits are generated and the fatigue life is shortened. Further, it is known that the fatigue strength of 12Cr steel or the like generally used for a compressor blade material is reduced in a salt water environment or an acid solution environment. Such an example is described, for example, on pages 379 to 380 of the Allianz Damage Prevention Handbook (issued on March 1, 1991 by the Japan Machinery Insurance Federation).

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

  At this time, in order to guarantee the reliability of the blade, it is necessary to accurately estimate the actual vibration stress generated in the blade and the corrosive environment to which the blade is exposed, and evaluate the strength and the remaining life. However, it is difficult to accurately evaluate the actual vibration stress of the blade and the actual corrosive environment, and if the water cleaning shown in Patent Document 1 is frequently performed, the corrosive environment is improved. Generally, it is necessary to perform the operation when the gas turbine is stopped, and it is difficult to perform this frequently from the viewpoint of operation and economy.

  The present invention has been made in view of this, and an object thereof is to provide a gas turbine capable of extending the life of a compressor blade.

  That is, the present invention comprises a turbine, a compressor, a combustor that mixes discharge air and fuel from the compressor, and supplies the fuel gas to the turbine, and a casing that includes 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 intake air of a compressor, a data collection device, a computer, a recording device, and a mechanism for circulating dry air in the casing And

  According to the present invention, it is possible to provide a gas turbine capable of extending the life of a compressor blade.

  Hereinafter, the present invention will be described in detail based on the illustrated embodiments. FIG. 1 shows the gas turbine equipment. 1 is a gas turbine body, 2a is a compressor, 14a is a turbine, 15 is a combustor, and 18 is a compressor air inlet.

  The rotor 2 of the compressor is formed by implanting a compressor rotor blade 7 on a rotor shaft via a dovetail. The rotor shaft is formed by connecting a compressor stub shaft 4 and a compressor disk 5 with a compressor stacking bolt 6. The compressor casing 3 is provided with a compressor vane 8 inside thereof. The compressor vane 8 is formed by being fitted into a groove provided on the inner wall of the compressor casing, and sucked from a compressor air suction port 18. The air is rectified and sent to the compressor blades 7.

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

  Fuel is combusted in the combustor 15, and the generated combustion gas is rectified by the turbine nozzle 16 to rotate 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 the turbine base 17.

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

  FIG. 2 is an enlarged view showing how the pressure sensor 44 is attached. In this example, a pressure sensor mounting hole is drilled in the compressor casing 3, and the pressure sensor 44 is mounted in this hole. In addition, as this pressure sensor, what is generally employ | adopted may be sufficient, for example, a strain gauge type pressure sensor etc. may be sufficient. As shown in this figure, by attaching the pressure sensor 44 to each stage 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 stage Variation is measured.

  Returning to FIG. 1, the pressure fluctuation data measured by the pressure sensor 44 and recorded in the recording device 29 is held in the data recording device 31 using the calculator 30. The data recording device 31 holds a stress analysis model of the compressor blade. The computer 30 reads the pressure fluctuation data and the compressor blade stress analysis model described above, and calculates the response stress due to the pressure fluctuation of the compressor blade using the pressure fluctuation data and the compressor blade stress analysis model.

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

  FIG. 3 shows a system configuration diagram for evaluating the remaining life of the compressor blades in one embodiment of the present invention. This compressor blade remaining life evaluation system includes a data input / output control subsystem 47, vibration analysis subsystem 48, fatigue damage analysis subsystem 49, waveform analysis subsystem 50, remaining life evaluation subsystem 51, and database 52. It is configured. In addition, the arrow in a figure has shown the flow of the data between each apparatus.

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

  FIG. 4 (b) shows an example of pressure fluctuation used for vibration analysis. The waveform at the time of turning stall at the time of gas turbine ascending / descending when the compressor blade generates the largest vibration stress during its operation. Is shown. Rotating stall is a pressure fluctuation phenomenon peculiar to a compressor, and compressor blades and stationary blades are excited, and these blades generate higher vibrational stress than in steady operation.

  FIG. 5 shows the results when a strain gauge is attached to the compressor vane and the stress is measured. As is apparent from this measurement result, it can be seen that a rotating stall occurs when the rotational speed is around 70% of the rated rotational speed, and the stress of the blades increases. The stress at the time of rotating stall of the blade is the main factor of fatigue damage. By obtaining this stress with high accuracy, the fatigue damage of the blade can be accurately determined.

FIG. 6 shows a mechanism for turning stall. Rotating stall is a phenomenon in which a stalled cell in which a separation zone is generated in a blade and the flow is blocked while the compressor is operated at a speed other than rated operation rotates. The blade is excited by the passage of the stall cell. The excitation frequency of the wing is expressed by the following equation, and the coefficient a is known to be about 0.5.
fs = n · a · frps · j (1)
Here, fs is the blade excitation frequency, n is the number of stalled cells, a is a coefficient, and frps is the rotational frequency of the rotor. J is an integer.

  Note that the pressure fluctuation waveform shown in FIG. 4B is for the case where the turning stall cell is 1 (n = 1). FIG. 4A shows a rotor rotation pulse, and shows the time required for one rotation with 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 turning stall is represented by a multiple wave j = 1, 2, 3, 4... Of the fundamental wave of n = 1 represented by Equation 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 turning stall waveform becomes large when the rotation speed is around 70% of the rated rotation, and the fifth harmonic of the fundamental wave approaches the natural frequency of the blade. For this reason, as shown in FIG. 5, the blade stress increases when the rotational speed is in the vicinity of 70% of the rated rotational speed.

  FIG. 8 shows a mechanism having a spectrum in which the frequency of the pressure waveform at the time of turning stall is expressed by an equation. The fluctuation pressure waveform close to the trapezoid of FIG. 4B was simplified and modeled 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,...

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

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

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

  When the time history waveform of stress is obtained by frequency response analysis taking into account the plurality of pressure fluctuation peaks shown in FIG. 10, a time history waveform of a sine wave having each pressure peak obtained by frequency response analysis is generated. These are added together to obtain a time history waveform of stress. As shown in FIG. 8, the pressure waveform of the rotating stall is obtained by adding the harmonics of the fundamental wave without any phase difference, so that this method can be easily applied. In addition, 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 one-degree-of-freedom response curve. The stress analysis model may be a stress analysis model that obtains stress fluctuation from pressure fluctuation by beam calculation or the like in addition to the finite element method analysis model.

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

  In cumulative fatigue damage analysis, the minor and modified minor laws are calculated using the stress amplitude, stress frequency, blade actual corrosion environment data, and time strength data of the blade material in the corrosive environment obtained from the stress frequency analysis described above. Cumulative fatigue damage analysis is performed to calculate the cumulative blade damage. The cumulative damage analysis result obtained by the analysis is held in the database 52. Then, the cumulative fatigue damage calculated for each operation is added and held in the database 52. The time intensity diagram used for cumulative damage refers to the actual corrosion environment data of the compressor blade, and uses the time strength diagram corresponding to the blade corrosion environment. The actual corrosive environment of the blade can be obtained by analyzing the cleaning liquid when the blade is cleaned. Instead of cumulative damage analysis, crack growth analysis using fracture mechanics may be used.

  The remaining life evaluation subsystem 51 can calculate the allowable number of start / stop operations using the cumulative damage analysis result data stored in the database 52 and the limit value of the cumulative damage rate. With the program configuration described above, the accumulated fatigue damage of the blades can be accurately and quickly evaluated, and the compressor blade replacement time can be determined based on the accumulated fatigue damage, thereby improving the reliability of the gas turbine. it can.

  FIG. 12 shows another embodiment. Although the configuration is almost the same as that of the invention shown in FIG. 1, in this embodiment, a thermocouple 46 is attached to the compressor casing 3. As shown in FIG. 2, the thermocouple 46 has a thermocouple mounting hole formed in the compressor casing 3, and the thermocouple 46 is mounted in the hole. The temperature of the inner surface of the casing 3 can be measured with 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 blades embedded in the casing can be regarded as 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 a mechanism for circulating the dry air configured by the dry air generator 52, the dry air pipe 53 and the valve 54 into the casing 3. The dry air generating device 52 and the valve 54 are controlled by a control signal sent from the computer 30 and the control device 29 via the signal line 38. The dry air pipe 38 is connected to an extraction port position of the casing 3, an air intake port, and the like, and is provided so as to guide the dry air into the casing 3. The dry air generating device is generally a device for exchanging humidity using a rotating channel type absorber.

  In this invention, it has the apparatus which measures the relative humidity and external temperature of the external air of the casing 3 comprised from the humidity sensor 55, the temperature sensor 57, and sensor amplifier 56. FIG. The measured air relative humidity data and 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 at the same location, and the gas turbine is stopped when the humidity and temperature of the intake air of the gas turbine are measured, such as in the enclosure containing the compressed air inlet 18 or the gas turbine. It may be installed so as to measure the humidity and temperature of the air that may flow in. Even when the gas turbine is stopped, since the outside air flows in from the opening of the casing, the humidity and temperature of the air that may flow in are measured.

  FIG. 12 is used to show the control steps of the present invention. When the gas turbine is stopped, the saturated steam temperature to of the outside air is obtained by the calculator 30 from the data of the outside air humidity sensor 55 and the outside air temperature sensor 57. A temperature ti on the inner surface of the casing is measured by a thermocouple 46 attached to the casing 3. When to / ti> b, the computer 30 activates the dry air generation device 52 via the control device 29. b is a limit value, and it is considered that water vapor contained in the air in the compressor is condensed on the blade surface of the compressor when b = 1. b is set to 1 or less considering the safety factor. In the present invention, dry air is allowed to flow so that outside air of to> ti does not circulate in the casing. Therefore, dry air may be circulated when ti-to <C (C is an integer of 0 or more).

  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. By this invention, the dew point of the air in a gas turbine casing can be made below into the metal temperature of a compressor blade. Thereby, condensation of moisture on the surface of the compressor blade can be prevented, and the corrosive environment can be improved, so that the reliability of the compressor blade can be enhanced. Similarly, the relative humidity of the air in the casing 3 may be predicted, and the dry air may be circulated in the casing when the relative humidity falls below a certain limit value. The limit value of 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 and removing dirt from the compressor. In general, 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 has 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 the valves 22, 23 and 24, respectively. It is connected by a pipe line.

  In the present embodiment, the valves 20, 22, 23, and 24 are controlled to be opened and closed by the control device 29 via the signal line 28. For example, when the valve 22 is opened, the valves 23 and 24 are closed, and the valve 20 is further opened, pure water is discharged from the water washing nozzle 19 and the compressor blades can be washed with pure water. Similarly, the cleaning liquid tank 26 and the cleaning liquid tank 27 can be cleaned with the cleaning liquid. Further, the amount of the cleaning liquid released is controlled by the flow meter 21 and the control device 29, and the amount of the cleaning liquid input is recorded in the computer 30. With these devices, the compressor blades 7 and 8 are washed, and the blades are cleaned to restore the compressor performance.

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

  The opening / closing control of the valve 34, the acquisition of the flow meter 36 data, the control of the pH measurement mechanism 36, and the acquisition of data are performed by the control device 29 via the signal line 38. In the present embodiment, a computer 30 in which measurement data is recorded, displayed, valve opening / closing, control of a pH measurement mechanism including sample collection, control of a water cleaning mechanism, and recording of the amount of spray cleaning liquid are connected to the control device 29 by a signal line. To do. In addition, the present embodiment also includes a recording device 31 for recording measurement data and accumulating life data of a corrosive environment.

  In the embodiment of FIG. 14, unlike the embodiment of FIG. 13 described above, the cleaning wastewater is collected by the sample collection device 35, and the collected sample is analyzed off-line. According to this embodiment, since it is possible to analyze the washing wastewater offline, a detailed analysis at the laboratory level is possible. The analysis content includes pH analysis, electrical conductivity analysis, chromatography, EDX, various elemental analysis, chemical analysis, and the like. According to these analyses, the corrosive environment under the working environment of the compressor blade can be evaluated.

  FIG. 15 has a configuration substantially similar to that of the invention shown in FIG. The difference from FIG. 13 is that the computer 30 and the recording device 31 are connected to each other via an internet line. Thereby, it becomes possible to analyze using the computer 31 and the recording device 31 which exist in a remote place with higher performance than the computer of the power generation facility. As a result, it is possible to evaluate the remaining life of the blade with higher accuracy, and to improve the reliability of the gas turbine.

  As described above, in the case of a gas turbine formed in this way, for example, it is possible to accurately evaluate the vibration stress and the corrosion environment state at the time of rotating stall of the compressor stationary blade, and the stress and environment In addition, since the remaining life evaluation is performed, a highly accurate remaining life evaluation can be performed and the reliability of the gas turbine can be improved. Further, when the gas turbine is stopped, the temperature inside the casing is measured by the temperature sensor inside the casing, the relative humidity inside the casing is calculated by the outside air temperature sensor and the humidity sensor, and the relative humidity inside the casing has a certain limit value. The dry air is circulated in the casing by a mechanism that circulates the dry air when it becomes below, which makes it possible to lower the dew point of the air in the casing and prevent condensation of moisture on the blade surface. The corrosive environment can be improved.

It is a vertical side view which shows one Example of the gas turbine of this invention. It is a gas turbine sectional view showing the important section of the gas turbine of the present invention. It is a program block diagram of 1st Example of this invention. It is fluctuating pressure data in the 1st example of the present invention. It is the generated stress data of the compressor blade | wing explaining the 1st Example of this invention. It is explanatory drawing of turning stall. It is explanatory drawing of blade stress generation | occurrence | production by the turning stall explaining the 1st Example of this invention. It is explanatory drawing of the frequency characteristic of the pressure fluctuation by the turning stall explaining the 1st Example of this invention. It is a stress prediction model which shows the 1st Example of this invention. It is a stress prediction result which shows the 1st Example of this invention. It is explanatory drawing of the stress prediction which shows the 1st Example of this invention. It is sectional drawing of the gas turbine which shows the other Example of this invention. It is sectional drawing of the gas turbine which shows the other Example of this invention. It is sectional drawing of the gas turbine which shows the other Example of this invention. It is sectional drawing of the gas turbine which shows the other Example of this 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 blade, 8 ... Compressor stationary blade, 9 ... Turbine Rotor, 10 ... Turbine stub shaft, 11 ... Turbine disk, 12 ... Distance piece, 13 ... Stacking bolt, 14 ... Turbine blade, 15 ... Combustor, 16 ... Turbine stationary blade, 17 ... Turbine base, 18 ... Compressor air Suction port, 19 ... water cleaning nozzle, 20 ... valve, 21 ... flow meter, 22 ... valve, 23 ... valve, 24 ... valve, 25 ... pure water tank, 26 ... cleaning liquid (surfactant) tank, 27 ... cleaning liquid ( Petroleum-based) tank, 28 ... signal line, 29 ... control and recording device, 30 ... computer, 31 ... data recording device, 32 ... drainage drain, 33 ... valve, 34 ... flow 35 ... Sample collection device, 36 ... pH measurement device, 37 ... Valve, 38 ... Signal line, 39 ... Internet line, 44 ... Pressure sensor, 45 ... Sensor amplifier, 46 ... Thermocouple, 47 ... Data input / output control sub 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 56 ... sensor amplifier, 57 ... temperature sensor.

Claims (4)

In a gas turbine comprising a turbine, a compressor, a combustor that mixes discharge air and fuel from the compressor and supplies the fuel gas to the turbine, and a casing containing the turbine and the compressor.
The has a dry air generator for circulating a dry燥空air in the casing, a sensor for measuring the humidity and temperature of the intake air in the casing, a sensor for measuring the casing surface temperature,
When the gas turbine is stopped, the sensor measures the temperature and humidity of the air, obtains the saturated steam temperature of the air from the temperature and humidity, and determines the saturated steam temperature and the casing inner surface temperature. A gas turbine characterized in that, when the ratio satisfies a certain condition, the dry air flows from the dry air generator into the casing . In claim 1,
The gas turbine in which the predetermined condition is saturated steam temperature / surface temperature> b, and b is a value of 1 or less. 3. A gas turbine according to claim 1 or 2, comprising a water cleaning device for injecting cleaning water from a compressor air suction port. 4. A gas turbine according to claim 1, 2 or 3, wherein said gas turbine is connected to a remote computer and recording device via an internet line.

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