JP2019214981A - Performance diagnostic method of gas turbine, and diagnostic device of gas turbine - Google Patents

Abstract

To provide a performance diagnostic method of a gas turbine and a diagnostic device of the gas turbine, capable of diagnosing the performance degradation of the gas turbine during operation.SOLUTION: A performance diagnostic method of a gas turbine includes a first process ST12 for executing a performance test of total load of a reference gas turbine, a second process ST13 for acquiring a turbine expansion ratio and a mass flow rate of the reference gas turbine from a measured value and numerical value hydrodynamics analysis based on the measured value, a third process ST14 for executing a performance test of a diagnostic object gas turbine and acquiring a turbine expansion ratio and a mass flow rate, and a fourth process ST15 for diagnosing the performance of the diagnostic object gas turbine by comparing the turbine expansion ratio and the mass flow rate of the reference gas turbine with the turbine expansion ratio and the mass flow rate of the diagnostic object gas turbine.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a gas turbine performance diagnosis method and a gas turbine diagnosis apparatus, and for example, relates to a gas turbine performance diagnosis method and a gas turbine diagnosis apparatus that can determine deterioration of the performance of a gas turbine during operation.

Conventionally, a damage diagnosis device for diagnosing damage to a power generation facility (for example, see Patent Literature 1) and a method for diagnosing the life of high-temperature components in a gas turbine have been proposed (for example, see Patent Literature 2). In the damage diagnosis apparatus described in Patent Literature 1, data obtained by a sensor provided in a power generation facility is converted into boundary conditions of a numerical analysis model of damage, and damage analysis of equipment is performed by a numerical analysis model using the converted boundary conditions. Is carried out.
Further, in the life diagnosis method described in Patent Document 2, the local gas temperature transmitted to each high-temperature component is calculated for each assumed operating condition, and a correlation diagram between the calculated local gas temperature and each operating condition is created. . Then, for the desired high-temperature component, based on the created correlation diagram and the operating conditions accumulated along with the actual operation, the local gas temperature corresponding to each operating condition during the actual operation is extracted from the correlation diagram and extracted. The obtained operation time for each local gas temperature is obtained from the operation information. Then, each of the acquired operation times is weighted by a weighting factor to accumulate the respective operation times, and the accumulated operation time is compared with a reference value defined for the high-temperature component to determine the remaining life.

Japanese Patent No. 3788901 Japanese Patent No. 4354358

  By the way, in a gas turbine such as a power generation facility, in order to diagnose turbine performance during operation of the turbine main body, the temperature and pressure of combustion gas at a turbine inlet and combustion exhaust gas discharged from a turbine outlet are measured. Diagnosing internal efficiency is being considered. However, since the temperature of the combustion gas supplied from the combustor exceeds 1000 ° C. at the turbine inlet of the turbine body, the temperature and pressure of the combustion gas at the turbine inlet cannot be measured by the conventional technique, and the internal efficiency of the turbine is measured. It was difficult to diagnose the performance of the gas turbine.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a gas turbine performance diagnosis method and a gas turbine performance diagnosis device capable of diagnosing performance deterioration of an operating gas turbine.

  A method for diagnosing performance of a gas turbine according to the present invention includes a compressor that compresses air to obtain compressed air, a combustor that mixes the compressed air and fuel to burn and obtain combustion gas, and a turbine blade using the combustion gas. A method for diagnosing the performance of a gas turbine comprising: a turbine body that rotates and rotates a turbine body for discharging combustion exhaust gas, wherein a performance test of a full load of the reference gas turbine is performed to execute the compressed air. Temperature, the pressure of the compressed air, the outlet temperature of the gas turbine, the outlet pressure of the gas turbine, and a first step of obtaining a measured value of a mass flow rate that is a sum of the air and the fuel, and the measured value And a second step of obtaining a turbine expansion ratio and a mass flow rate of the reference gas turbine by a numerical fluid dynamics analysis based on the measurement values, and the diagnosis target gas turbine Performing a performance test to obtain a turbine expansion ratio and a mass flow rate, and comparing the turbine expansion ratio and the mass flow rate of the reference gas turbine with the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed. And diagnosing the performance of the gas turbine to be diagnosed.

  According to the method for diagnosing performance of a gas turbine, it is possible to obtain the turbine expansion ratio and the mass flow rate of the reference gas turbine without obtaining the temperature and pressure of the combustion gas supplied from the compressor to the turbine body by the numerical fluid analysis. Becomes possible. This makes it possible to compare the turbine expansion ratio and the mass flow rate of the reference gas turbine with the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed after the reference gas turbine has been operated for a predetermined time. As a result, it is possible to diagnose the turbine performance of the gas turbine to be diagnosed during operation, which has been difficult in the past, and it can be expected to improve the efficiency by appropriate maintenance, and to reduce the fuel cost by reducing the labor force by extending the periodical inspection and the like.

  In the method for diagnosing performance of a gas turbine according to the present invention, a step of acquiring a shape of a turbine stationary blade and a turbine moving blade of the reference gas turbine and acquiring a clearance between the turbine stationary blade and the turbine moving blade is performed. Preferably, it further includes.

  In the method for diagnosing performance of a gas turbine according to the present invention, it is preferable that a tip clearance and a nozzle clearance between the turbine stationary blade and the turbine blade are acquired as the clearance.

  In the method for diagnosing performance of a gas turbine according to the present invention, in the fifth step, a turbine expansion ratio and a mass flow rate of the gas turbine to be diagnosed are compared with a turbine expansion ratio and a mass flow rate of the reference gas turbine. Preferably, the performance of the gas turbine to be diagnosed is diagnosed. According to this method, the deviation of the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed with respect to the reference line can be grasped, so that the degree of performance degradation of the gas turbine to be diagnosed can be easily grasped.

  In the method for diagnosing performance of a gas turbine according to the present invention, in the third step, a relationship between a pressure of the compressed air and an outlet temperature of the gas turbine by a numerical fluid dynamics analysis is acquired, and a turbine of the reference gas turbine is obtained. It is preferable to determine by adjusting the expansion ratio and the mass flow rate. According to this method, the analysis result of the turbine expansion ratio and the mass flow rate by the fluid dynamic analysis can be adjusted and determined in consideration of the reference state of the gas turbine to be measured. Diagnosis can be made with high accuracy.

  In the method for diagnosing performance of a gas turbine according to the present invention, it is preferable that in the first step, a tip clearance and a nozzle clearance between the turbine stationary blade and the turbine blade are acquired as the clearance. With this method, the amount of leakage of the combustion gas in the turbine body can be grasped, so that the accuracy of the result of the computational fluid analysis is further improved.

  A gas turbine diagnostic device according to the present invention includes a compressor that compresses air to obtain compressed air, a combustor that mixes the compressed air and fuel and burns to obtain combustion gas, and a turbine blade using the combustion gas. A gas turbine including a turbine body that rotates and discharges combustion exhaust gas, a turbine expansion ratio and a mass ratio of the gas turbine that are obtained in advance by numerical fluid analysis, and a turbine of a gas turbine to be diagnosed after a predetermined engine operation. A diagnosis unit that diagnoses the performance of the gas turbine based on a relationship between an expansion ratio and a mass ratio.

  According to the gas turbine diagnostic apparatus, it is possible to acquire the turbine expansion ratio and the mass flow rate of the reference gas turbine without acquiring the temperature and the pressure of the combustion gas supplied from the compressor to the turbine body by the numerical fluid analysis. It becomes possible. This makes it possible to compare the turbine expansion ratio and the mass flow rate of the reference gas turbine with the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed after the reference gas turbine has been operated for a predetermined time. As a result, it is possible to diagnose the turbine performance of the gas turbine to be diagnosed during operation, which has been difficult in the past, and it is expected that the efficiency will be improved by appropriate maintenance, and the fuel cost will be reduced by reducing the labor force by extending the periodical inspection and the like.

  According to the present invention, it is possible to realize a gas turbine performance diagnosis method and a gas turbine performance diagnosis device capable of diagnosing performance deterioration of an operating gas turbine.

FIG. 1 is a schematic diagram of a gas turbine power generator according to an embodiment of the present invention. FIG. 2 is a schematic partial cross-sectional view of the gas turbine according to the embodiment of the present invention. FIG. 3 is a flowchart schematically illustrating a method for diagnosing performance of a gas turbine according to the embodiment of the present invention. FIG. 4 is a diagram showing a relationship between the pressure of the compressed air and the combustion exhaust gas of the gas turbine according to the embodiment of the present invention. FIG. 5 is a flowchart schematically showing a third step of the method for diagnosing performance of a gas turbine according to the embodiment of the present invention. FIG. 6 is a diagram showing the relationship between the turbine expansion ratio and the mass flow rate of the reference gas turbine and the gas turbine to be diagnosed according to the embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments, but can be implemented with appropriate modifications.

  First, an outline of a gas turbine power generation device using the gas turbine diagnostic method according to the present embodiment will be briefly described. FIG. 1 is a schematic diagram of a gas turbine power generation device 1 according to the present embodiment. As shown in FIG. 1, a gas turbine power generator 1 according to the present embodiment includes a gas turbine 11 that rotates a turbine by burning a mixture of fuel and air, and a combustion exhaust gas discharged from the gas turbine 11. An exhaust heat recovery boiler 12 for recovering heat and a power generator 13 connected to the gas turbine 11 are provided. The combustion exhaust gas whose exhaust heat has been recovered by the exhaust heat recovery boiler 12 is discharged as an exhaust gas from the chimney 14 to the outside as an exhaust gas. In addition, the gas turbine power generation device 1 may be a combined power generation system (combined cycle) that generates power using steam generated using heat recovered by the exhaust heat recovery boiler 12.

  The gas turbine 11 compresses air supplied to the gas turbine 11 to produce compressed air, and mixes compressed air supplied from the compressor 111 with fuel supplied to the gas turbine 11 for combustion. A combustor 112 that is made to be a combustion gas is provided, and a turbine body 113 that is supplied with the combustion gas from the combustor 112 and discharges a combustion exhaust gas. The compressor 111 and the turbine main body 113 are connected by a turbine shaft 114, and the generator 13 is connected to the turbine shaft 114.

  The air supply line 21 that supplies air to the compressor 111 is connected to the compressor 111. Further, a flue gas discharge line 22 for discharging the flue gas of the turbine body 113 is connected between the turbine body 113 and the chimney 14. An exhaust heat recovery boiler 12 is provided between the turbine body 113 and the chimney 14 in the flue gas exhaust line 22. Between the compressor 111 and the combustor 112, a compressed supply air line 23 for supplying compressed air from the compressor 111 to the combustor 112 is provided. A combustion gas supply line 24 that supplies combustion gas from the combustor 112 to the turbine body 113 is provided between the combustor 112 and the turbine body 113. Further, a fuel supply line 25 for supplying fuel to the combustor 112 is connected to the combustor 112. As the fuel, light oil or the like separated from heavy oil fuel by distillation is used.

  The gas turbine 11 has a measuring unit 31 that measures the temperature and pressure of the compressed air flowing through the compressed air supply line 23, and the temperature and pressure of the combustion exhaust gas flowing through the flue gas exhaust line 22 and the outlet temperature and pressure of the gas turbine 11. A measuring unit 32 for measuring the outlet pressure. The measurement unit 31 transmits the measured temperature and pressure of the compressed air to the diagnosis unit 33. The measuring unit 32 transmits the measured outlet temperature and outlet pressure of the gas turbine 11 to the diagnostic unit 33. The diagnostic unit 33 is based on the temperature and pressure of the compressed air transmitted from the measuring units 31 and 32, the outlet temperature and outlet pressure of the gas turbine, the mass flow rate based on the sum of the air and fuel supplied to the gas turbine 11, and the like. The performance of the gas turbine 11 is diagnosed by calculating the turbine expansion ratio and the mass flow rate.

  FIG. 2 is a schematic partial cross-sectional view of the gas turbine 11 according to the present embodiment. As shown in FIG. 2, the gas turbine 11 includes a compressor 111 and a turbine main body 113 connected to each other by a turbine shaft 114. The compressor 111 is configured as, for example, an axial compressor, and sucks air from a suction port to increase the pressure. A combustor 112 is connected to a discharge port of the compressor 111. The compressor 111 supplies compressed air to the combustor 112 from a discharge port. The combustor 112 mixes and burns the fuel and the compressed air supplied from the compressor 111. In the combustor 112, the compressed air discharged from the compressor 111 is supplied to the combustor 112. The combustor 112 mixes the compressed air and the fuel and raises the temperature to 1000 ° C. or higher. Further, the combustor 112 supplies a high temperature combustion gas of 1000 ° C. or higher to the turbine body 113. The gas turbine 11 is provided with a cooling air supply line (not shown) for supplying compressed air from the compressor 111 to the turbine body 113. The turbine shaft 114 is provided rotatably in the axial direction.

  The turbine main body 113 includes a plurality (three in this embodiment) of turbine vanes 115-1, 115-2, and 115-3 fixed to the inner wall of the casing 113A. Turbine blades 116-1, 116-2, and 116-3 are attached to the turbine shaft 114 of the turbine main body 113 in correspondence with the respective turbine stationary blades 115-1, 115-2, and 115-3. . The turbine vanes 115-1, 115-2, 115-3 and the turbine blades 116-1, 116-2, 116-3 are provided alternately in the axial direction of the turbine shaft 114. One end of the turbine shaft 114 is connected to the rotating shaft of the compressor 111, and the other end is connected to the rotating shaft of the generator 13. Although FIG. 2 illustrates an example of a single-row turbine body 113 having three stages of cascades, the turbine body 113 is not limited to this. The cascade of the turbine main body 113 is not limited to three stages, but may be, for example, four or more stages. Further, the turbine body 113 may be a two-shaft turbine provided with a high-pressure turbine or a low-pressure turbine.

Between the turbine blades 116-1 and the casing 113A is the tip clearance _{d 11} as a predetermined interval is provided. Between the turbine blades 116-2 and the casing 113A is the tip clearance _{d 12} is provided as a predetermined interval. Between the turbine blades 116-3 and the casing 113A is the tip clearance _{d 13} as a predetermined interval is provided. Between the turbine stator blades 115-1 and the turbine shaft 114, the nozzle clearance _{d 21} as a predetermined interval is provided. Between the turbine stator blades 115-2 and the turbine shaft 114, the nozzle clearance _{d 22} as a predetermined interval is provided. Between the turbine stator blades 115-3 and the turbine shaft 114, the nozzle clearance _{d 23} as a predetermined interval is provided.

  In the gas turbine 11, the compressed air supplied from the compressor 111 via the compressed air line 23 is burned together with the fuel in the combustor 112, and the compressed air is supplied to the turbine body 113 via the combustion gas line 24 as a high-temperature and high-pressure combustion gas. It is supplied into the casing 113A. As a result, the combustion gas expands in the casing 113A, whereby the turbine shaft 114 rotates and the generator 13 is driven. That is, the pressure of the combustion gas supplied into the casing 113A is reduced by the turbine stationary blades 115-1, 115-2, and 115-3 fixed to the casing 113A. Then, the kinetic energy generated thereby is converted into rotational torque via each turbine rotor blade 116-1, 116-2, 116-3 attached to the turbine shaft 114. Then, the rotational torque generated by each of the turbine blades 116-1, 116-2, 116-3 is transmitted to the turbine shaft 114, and the generator 13 is driven. The rotation of the turbine shaft 114 is also used for driving the compressor 111. In such a gas turbine 11, since high-temperature and high-pressure combustion gas is supplied, the turbine stationary blades 115-1, 115-2, 115-3 and the turbine blades 116-1, 116-2, 116-3 are formed. to degrade. For this reason, the internal efficiency of the gas turbine 11 decreases with the operation time from the time of new installation or the periodical inspection, and the performance of the gas turbine 11 deteriorates.

The present inventors consider that the performance deterioration of the gas turbine 11 described above is caused by the deformation and the tip clearance d of the turbine stationary blades 115-1, 115-2, 115-3 and the turbine rotor blades 116-1, 116-2, 116-3. _11, by noting _{d 12, d 13} and a change in clearance, such as a nozzle clearance _{d 21, d 22, d 13} . The present inventors use CFD (computational fluid dynamics) to provide a reference without measuring the temperature and pressure of the combustion gas at the inlet of the turbine main body 113, which is at high temperature and high pressure. The present inventors have found that the performance of the gas turbine to be diagnosed can be diagnosed by calculating the turbine expansion ratio and the mass flow rate of the gas turbine 11, and have completed the present invention.

  Hereinafter, the gas turbine performance diagnosis method according to the present embodiment will be described in detail. The method for diagnosing performance of a gas turbine according to the present embodiment includes a compressor 111 for compressing air to obtain compressed air as shown in FIG. This is a method for diagnosing the performance of a gas turbine 11 comprising: a combustor 112 for obtaining a gas turbine; and a turbine main body 113 for rotating a turbine blade by the combustion gas and discharging a combustion exhaust gas.

  FIG. 3 is a flowchart schematically showing a gas turbine performance diagnosis method according to the present embodiment. As shown in FIG. 3, the method for diagnosing performance of a gas turbine according to the present embodiment obtains the shapes of the turbine vanes and turbine blades of the reference gas turbine, and obtains the clearance between the turbine vanes and turbine blades. And the performance test of the full load of the reference gas turbine is performed, and the temperature of the compressed air, the pressure of the compressed air, the outlet temperature of the gas turbine, the outlet pressure of the gas turbine, and the air and fuel And a third step ST13 of obtaining a turbine expansion ratio and a mass flow rate of a reference gas turbine by a measured value and a numerical fluid dynamics analysis based on the measured value. And a fourth step ST14 of performing a performance test of the gas turbine to be diagnosed to obtain a turbine expansion ratio and a mass flow rate, and a turbine expansion ratio of a reference gas turbine. And fine mass flow rate, by comparing the turbine expansion ratio and mass flow of the diagnosis target gas turbine, and a fifth step ST15 to diagnose the performance of the diagnostic target gas turbine. Hereinafter, each step will be described in detail. Note that the first step may be performed as needed.

  In the first step ST11, the shapes of the turbine stationary blade and the turbine moving blade of the gas turbine 11 of the reference gas turbine are acquired. As the reference gas turbine, a gas turbine having a higher turbine efficiency than the gas turbine to be diagnosed, such as a newly installed gas turbine before the start of operation and a gas turbine after a periodic inspection, is used. The shapes of the turbine vanes and turbine blades may be obtained by, for example, 3D scanning the turbine vanes and turbine blades with a laser with the gas turbine casing open, or may be obtained from design data or the like. Good. If the turbine vane and the turbine blade are of the same model, 3D scan data and the like can be used.

  In the first step ST11, a clearance between the turbine stationary blade and the turbine rotor blade of the reference gas turbine is obtained. As the clearance between the turbine stationary blade and the turbine rotor blade, for example, it is preferable to use the above-described tip clearance and nozzle clearance. Thereby, the amount of leakage of the combustion gas in the turbine body 113 can be grasped, so that the accuracy of the result of the numerical fluid analysis is further improved. In addition, it is preferable to use an average value measured a predetermined number of times at a predetermined temperature as the clearance between the turbine vane and the turbine blade.

  In the second step ST12, a performance test of the full load of the reference gas turbine is performed. Here, the measurement unit 31 shown in FIG. 1 measures the temperature and pressure of the compressed air by actual measurement. The outlet temperature and the outlet pressure of the gas turbine 11 are acquired by the measuring unit 32. Then, the measurement units 31 and 32 transmit the measured temperature and pressure of the compressed air to the diagnosis unit 33. The diagnosis unit 33 calculates a mass flow rate from the sum of air and fuel supplied to the gas turbine, and calculates a mass flow rate, turbine efficiency, turbine expansion ratio, and the like of the reference gas turbine from each measurement value.

  In the third step ST13, the diagnostic unit 33 acquires the turbine expansion ratio and the mass flow rate of the reference gas turbine by the measurement values of the reference gas turbine in the second step ST12 and the numerical fluid dynamics analysis based on the measurement values. In the computational fluid dynamics analysis here, the relationship of gas turbine inlet pressure = compressor outlet pressure−combustor pressure loss is used. The diagnostic unit 33 calculates the mass flow rate, which is the sum of the temperature of the compressed air of the reference gas turbine, the pressure of the compressed air, the temperature of the outlet of the gas turbine, the pressure of the combustion exhaust gas, and the sum of air and fuel, using a numerical fluid dynamic analysis. Adjust according to. Based on the adjusted result, a plurality of relationships between the turbine expansion ratio and the mass flow ratio of the reference gas turbine are acquired. It is possible to acquire a turbine expansion ratio and a mass flow rate reference line for acquiring a turbine expansion ratio and a mass flow rate under each operating condition of the reference gas turbine by the computational fluid dynamics analysis.

  In the gas turbine 11, the pressure of the compressed air may fluctuate according to climatic conditions such as changes in the temperature and pressure of the atmosphere. Therefore, in the third step ST13, the reference state of the gas turbine 11 under climatic conditions may be grasped by changing the pressure of the compressed air. In this case, in the above-described third step ST13, the relationship between the pressure of the compressed air and the outlet temperature of the gas turbine is obtained, and the turbine expansion ratio and the mass flow rate of the reference gas turbine are adjusted and determined in consideration of the reference state. You may. Thereby, since the computational fluid dynamics analysis can be performed based on the reference state, the performance of the gas turbine can be more accurately diagnosed.

  Here, the relationship between the pressure of the compressed air of the gas turbine and the outlet temperature of the gas turbine will be described. FIG. 4 is a diagram showing the relationship between the pressure of the compressed air of the gas turbine and the outlet temperature of the gas turbine. In FIG. 4, the horizontal axis indicates the pressure of the compressed air, and the vertical axis indicates the outlet temperature of the gas turbine. As shown in FIG. 4, in a power plant, generally, when the pressure of the compressed air becomes equal to or higher than a predetermined value (in the example of FIG. 4, 1.2 or more: see the point P0), control is performed to decrease the pressure of the compressed air (solid line). L1). On the other hand, the general gas turbine 11 is designed such that the outlet temperature of the gas turbine 11 changes according to the change in pressure of the compressed air. Therefore, it is effective to adjust and determine the outlet temperature of the turbine 11 of the reference gas turbine by performing a performance test while changing the pressure of the compressed air. When the determination of the turbine expansion ratio and the mass flow rate cannot be performed well, the performance curve of the compressor, that is, the relationship between the compressor outlet pressure and the compressor outlet pressure may be used.

  Next, an example of the third step ST13 will be specifically described with reference to FIG. FIG. 5 is a flowchart schematically showing a third step in the method for diagnosing performance of a gas turbine according to the embodiment of the present invention. As shown in FIG. 5, in a third step ST13, a step ST31 of acquiring a turbine expansion ratio and a mass flow rate when a performance test is performed by operating a reference gas turbine at a reference pressure of compressed air, A step ST32 of obtaining a gas turbine outlet temperature by changing from the above, a step ST33 of obtaining a turbine expansion ratio and a mass flow rate by a computational fluid dynamics analysis using the changed compressed air pressure and the obtained gas turbine outlet temperature, and Step ST34 of determining whether acquisition of the turbine expansion ratio and the mass flow rate is necessary.

  In step ST31, first, the turbine expansion ratio and the mass flow rate when the performance test is performed by operating the reference gas turbine at the reference pressure of the compressed air are obtained by numerical fluid dynamics analysis. In the computational fluid dynamics analysis here, the relationship of gas turbine inlet pressure = compressor outlet pressure−combustor pressure loss is used. In the numerical fluid dynamics analysis, the inlet pressure of the gas turbine is output. Therefore, the turbine expansion ratio can be obtained by using the relationship of turbine expansion ratio = gas turbine inlet pressure / gas turbine outlet pressure. .

  Next, in step ST32, the gas turbine outlet temperature is acquired by changing the compressed air pressure of the reference pressure. Here, as shown in FIG. 4, the case where the reference gas turbine is operated at the reference pressure of the compressed air and the performance test is performed is set as the reference point P1. Then, when an auxiliary line (see a broken line L2) passing through a reference point P1 parallel to a design line (see a solid line L1 in FIG. 4) based on the design value of the reference gas turbine is drawn, and the pressure of the compressed air is changed on the auxiliary line. The gas turbine outlet temperature. In the example shown in FIG. 4, the outlet temperature of the gas turbine corresponding to the point P2 is obtained by reducing the pressure of the compressed air by 2.5%. In this manner, in FIG. 4, the auxiliary line (see the broken line L2) is drawn because the design line (see the solid line L1) and the reference pressure (see the reference point P1) when the gas turbine is actually operated are shifted. It is based on taking into account that there may be cases.

  Subsequently, in step 33, a turbine expansion ratio and a mass flow rate corresponding to the point P2 are acquired by a computational fluid dynamics analysis using the obtained pressure of the compressed air and the outlet temperature of the gas turbine corresponding to the obtained point P2. In the computational fluid dynamics analysis, the input pressure of the gas turbine 11 is output in the same manner as the calculation of the turbine expansion ratio at the reference pressure, so that the turbine expansion ratio = the inlet pressure of the gas turbine / the outlet pressure of the gas turbine. By using the relationship, a turbine expansion ratio is obtained.

  Next, at step 34, it is determined whether the pressure of the compressed air is further changed to obtain the turbine expansion ratio and the mass flow rate. Further, when it is necessary to obtain the turbine expansion ratio and the mass flow rate by changing the pressure of the compressed air (step ST34: Yes), the steps 31 to 33 are repeated. In the example shown in FIG. 4, the steps 31 to 33 are further repeated to operate the reference gas turbine with the pressure reduced by 5% with respect to the reference pressure (point P3) and to operate the reference gas turbine with respect to the reference pressure. The turbine expansion ratio and the mass flow ratio are obtained by a computational fluid dynamics analysis when the operation is performed with the pressure increased by 2.5% (point P4). It can be seen that the compressed air pressure and the gas turbine outlet temperature at these points P1 to P4 are similar to those obtained when a performance test is performed by operating the diagnosis target gas turbine at the reference pressure (point P5).

  Based on the result of such a computational fluid dynamics analysis, the deviation between the design line of the gas turbine (see the solid line L1 in FIG. 4) and the auxiliary line indicating the pressure when the gas turbine is actually operated (see the broken line L2 in FIG. 4). Can be adjusted and determined. As a result, the reference state of the reference gas turbine is taken into account, and a turbine expansion ratio and a mass flow rate that reflect the original performance of the reference gas turbine can be obtained, so that the performance of the gas turbine to be diagnosed can be more accurately diagnosed. Becomes possible.

  In the third step ST13, the input value of the temperature of the compressed air becomes equal to the actually measured value of the combustion temperature when the fuel is burned in the combustor 112, and the input values of the pressure of the compressed air and the pressure of the fuel become the compressed air. And the input value of the combustion gas flow rate is a value obtained by adding the fuel flow rate to the air flow rate supplied to the compressor 111 and the measured value and the numerical value. It is preferable to adjust the result of the fluid dynamic analysis. This makes it easier to match the measured value with the result of the computational fluid dynamics analysis, so that it is possible to easily obtain a reference line for the expansion ratio and the mass flow rate of the gas turbine.

  In the third step ST13, it is preferable that the adjustment is performed in consideration of the cooling air supplied from the compressor 111 to the turbine body 113. As a result, the result of the computational fluid analysis considering the cooling air is obtained, and the accuracy of the computational fluid analysis result is improved.

  In the third step ST13, it is preferable to adjust the temperature and pressure of the compressed air based on the outlet temperature and outlet pressure of the gas turbine. This makes it possible to easily match the measured value in the performance test of the reference gas turbine with the result of the computational fluid dynamics analysis. By performing the computational fluid dynamics analysis in this manner, the analysis result of the gas turbine to be diagnosed and the measurement result of the reference gas turbine can be matched with high accuracy.

  In the fourth step ST14, a performance test of the gas turbine to be diagnosed is performed to obtain a turbine expansion ratio and a mass flow rate. Here, the diagnosis unit 33 determines the turbine expansion ratio and the turbine expansion ratio based on the air and fuel supplied to the gas turbine 11, the temperature and pressure of the compressed air acquired by the measurement units 31 and 32, the outlet temperature and the outlet pressure of the gas turbine. Get the mass flow. Here, it is preferable to perform a performance test of the full load of the gas turbine to be diagnosed.

  In the fifth step ST15, the performance of the gas turbine to be diagnosed is diagnosed by comparing the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed obtained in the fourth step ST14. FIG. 6 is a diagram showing the relationship between the turbine expansion ratio and the mass flow rate of the reference gas turbine and the gas turbine to be diagnosed according to the present embodiment. In FIG. 6, the vertical axis indicates the turbine expansion ratio, and the horizontal axis indicates the mass flow rate.

  As shown in FIG. 6, when the performance test of the reference gas turbine was actually performed at the reference pressure of the compressed air and the performance test was performed (point P6), the pressure of the reference gas turbine was increased with respect to the reference pressure by the numerical fluid dynamic analysis. Is reduced by 2.5% (point P7), and when the pressure of the reference gas turbine is reduced by 5% with respect to the reference pressure by the numerical fluid dynamics analysis (point P8). When the state where the pressure of the reference gas turbine is increased by 2.5% with respect to the reference pressure by the numerical fluid dynamics analysis (point P9) is analyzed, the relationship between the turbine expansion ratio and the mass flow becomes substantially linear, A reference line L3 is obtained. On the other hand, when the performance of the gas turbine to be diagnosed is operated at the reference pressure and the performance test is performed (point P10), the result largely deviates from the reference line L3 based on the points P6 to P10. These points P6 to P10 correspond to points P1 to P5 shown in FIG. By diagnosing the turbine expansion ratio and the mass flow rate data of the gas turbine to be diagnosed on the diagram of the turbine expansion ratio and the mass flow rate of the reference gas turbine, it is possible to diagnose the performance degradation of the gas turbine to be diagnosed. Becomes possible. In addition, it is possible to diagnose the degree of deterioration based on the difference in the plotting position of the data of the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed with respect to the reference line L3. In this case, if the plot of the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed is located close to the reference line L3 of the turbine expansion ratio and the mass flow rate of the reference gas turbine, the turbine body of the gas turbine to be diagnosed It can be determined that the fluid resistance in 113 is large, and the shapes and clearances of the turbine vanes and turbine blades are close to those of the reference gas turbine. If the plot of the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed is far from the reference line L3 of the turbine expansion ratio and the mass flow rate of the reference gas turbine, the fluid of the turbine body 113 of the gas turbine to be diagnosed is located. It can be seen that the resistance has been reduced and at least one of the shape and clearance of the turbine vanes and turbine blades has changed. In addition, by acquiring the reference line L3 of the turbine expansion ratio and the mass flow rate of the reference turbine by the numerical fluid analysis in this manner, the case where the mass flow rate and the like change with the temperature and the atmospheric pressure with the seasonal change. However, the performance of the gas turbine 11 can be diagnosed.

  In the fifth step ST15, it is not always necessary to diagnose the performance by comparing the reference line L3 with the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed, and the turbine expansion ratio and the mass flow rate of the specific reference gas turbine are not required. The performance may be diagnosed by comparing the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed. In this case, if the turbine expansion ratio is large, it is judged that the change in the shape of the turbine rotor blade and the turbine vane from the reference gas turbine is small, and that the various clearances of the turbine rotor blade and the turbine vane are maintained and the performance deterioration is small. it can. If the turbine expansion ratio is small, the shape of the turbine blade and turbine vane from the reference gas turbine changes greatly, and it is judged that the performance has deteriorated due to changes in the various clearances of the turbine blade and turbine vane. it can.

  As described above, according to the above embodiment, the turbine expansion ratio and the mass flow rate of the reference gas turbine are obtained without acquiring the temperature and the pressure of the combustion gas supplied from the compressor to the turbine body by the numerical fluid analysis. It becomes possible to acquire. This makes it possible to compare the turbine expansion ratio and the mass flow rate of the reference gas turbine with the turbine expansion ratio and the mass flow rate of the gas turbine to be diagnosed after the reference gas turbine has been operated for a predetermined time. As a result, it is possible to diagnose the turbine performance of the gas turbine to be diagnosed during operation, which has been difficult in the past, and it is expected that the efficiency will be improved by appropriate maintenance, and the fuel cost will be reduced by reducing the labor force by extending the periodical inspection and the like.

  Further, according to the above embodiment, since the reference line L3 of the expansion ratio and the mass flow rate of the reference gas turbine can be drawn by the numerical fluid analysis, the reference line L3 is compared with the operation result of the gas turbine to be diagnosed. Accordingly, it is possible to efficiently diagnose the performance deterioration of the gas turbine 11.

  Further, according to the above-described embodiment, the temperature of the combustion gas can be analyzed by the numerical fluid analysis, and the life of the first-stage stationary blade 115-1 as an important component can be evaluated. Further, the pressure of the combustion gas, which is difficult to measure, can be accurately calculated from the fuel supply pressure.

  The present invention has an effect of a gas turbine performance diagnosis method and a gas turbine capable of diagnosing performance deterioration of an operating gas turbine, and for example, a gas turbine diagnosis of a device including various gas turbines such as a gas turbine power generation device. Can be used.

DESCRIPTION OF SYMBOLS 1 Gas turbine generator 11 Gas turbine 111 Compressor 112 Combustor 113 Turbine main body 113A Casing 114 Turbine shaft 115-1, 115-2, 115-3 Turbine stationary blade 116-1, 116-2, 116-3 Turbine rotor blade Reference Signs List 21 air supply line 22 combustion exhaust gas line 23 compressed gas supply line 24 combustion gas supply line 25 fuel supply line 31, 32 measuring unit 33 diagnostic unit

Claims (6)

A compressor that compresses air to obtain compressed air, a combustor that mixes the compressed air and fuel and burns to obtain combustion gas, and a turbine body that rotates turbine blades and discharges combustion exhaust gas by the combustion gas. A method for diagnosing the performance of a gas turbine having a gas turbine, comprising:
Perform a performance test of the full load of the reference gas turbine, the temperature of the compressed air, the pressure of the compressed air, the outlet temperature of the gas turbine, the outlet pressure of the gas turbine, and the sum of the air and the fuel A first step of obtaining a measurement value of a certain mass flow rate;
A second step of obtaining a turbine expansion ratio and a mass flow rate of the reference gas turbine by a numerical fluid dynamics analysis based on the measured values and the measured values;
Performing a performance test of the gas turbine to be diagnosed to obtain a turbine expansion ratio and a mass flow rate;
A fourth step of comparing the turbine expansion ratio and the mass flow rate of the reference gas turbine with the turbine expansion ratio and the mass flow rate of the diagnosis target gas turbine to diagnose the performance of the diagnosis target gas turbine. A method for diagnosing the performance of a gas turbine.   The performance of the gas turbine according to claim 1, further comprising a step of acquiring a shape of a turbine vane and a turbine blade of the reference gas turbine and acquiring a clearance between the turbine vane and the turbine blade. Diagnostic method.   The gas turbine performance diagnosis method according to claim 2, wherein a tip clearance and a nozzle clearance between the turbine stationary blade and the turbine blade are acquired as the clearance.   In the fourth step, a turbine expansion ratio and a mass flow rate of the reference gas turbine are compared with a turbine expansion ratio and a mass flow rate of the diagnosis target gas turbine, and the performance of the diagnosis target gas turbine is diagnosed. The method for diagnosing performance of a gas turbine according to any one of claims 1 to 3.   In the first step, a relationship between a pressure of the compressed air and an outlet temperature of the gas turbine obtained by a computational fluid dynamics analysis is obtained, and a turbine expansion ratio and a mass flow rate of the reference gas turbine are adjusted and determined. The method for diagnosing performance of a gas turbine according to any one of claims 1 to 4. A compressor that compresses air to obtain compressed air, a combustor that mixes the compressed air and fuel to burn and obtain combustion gas, and a turbine body that rotates turbine blades and discharges combustion exhaust gas by the combustion gas. Equipped gas turbine,
The performance of the gas turbine based on the relationship between the turbine expansion ratio and the mass ratio of the gas turbine, which is a reference obtained in advance by numerical fluid dynamics analysis, and the turbine expansion ratio and the mass ratio of the gas turbine to be diagnosed after a predetermined period of operation. And a diagnosis unit for diagnosing the gas turbine.

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