JP2004011458A - Stationary blade clocking device and its position control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stationary blade clocking device, achieving operation of consistently high efficiency at a vibration level not exceeding an allowable level by finding an optimum position for clocking a stationary blade in response to a change of an operating point and changing it at a real time, and also to provide its position control method. <P>SOLUTION: The method comprises: a scanning step S1 of scanning a downstream stationary blade train 4 corresponding to a blade train pitch in the peripheral direction; whole pressure measuring step S2 of measuring the whole pressure of the downstream stationary blade train 4 at its front edge and detecting a minimum whole pressure position P1; a downstream stationary blade train positioning step S3 of moving the downstream stationary blade train 4 to the minimum whole pressure position P1; a moving blade vibration comparing step S4 of detecting a vibration level of a moving blade and comparing it with a predetermined allowable level A1; and a downstream stationary blade train moving step S5 of moving the downstream stationary blade train 4 a predetermined distance to the peripheral direction when the vibration level of the moving blade exceeds the predetermine allowable level A1. The steps S4, S5 are repeated until the vibration level of the moving blade reaches the predetermined allowable level A1 or lower. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stationary blade clocking device that adjusts a circumferential position between stationary blade rows of an axial turbine or a compressor, and a position control method thereof.
[0002]
[Prior art]
FIG. 6 is a schematic configuration diagram of the aircraft engine 51 (jet engine). As shown in this figure, the jet engine includes a fan 52 for taking in air, a compressor 53 for compressing the taken-in air, a combustor 54 for burning fuel with the compressed air, and a fan 52 and a compressor using combustion gas from the combustor 54. A turbine 55 for driving the engine 53, an afterburner 56 for reburning to increase the thrust, and the like are provided.
[0003]
The afterburner 56 has a triangular cross section and the like, and comprises a frame holder (flame holder) 57 for forming a circulation area downstream and performing flame holding, a fuel nozzle 58 for ejecting fuel, an ignition plug 59 and the like, and an outer duct. The gas is ejected from an exhaust nozzle 62 through a liner 61 inside 60 to increase the thrust.
[0004]
In the above-described multi-stage axial compressors and axial turbines in jet engines and industrial gas turbines, if the number of blades in the upstream and downstream stationary blade rows sandwiching the moving blades is equal for the purpose of improving the efficiency, the circumferential It is necessary to adjust the direction position. Adjusting the circumferential positions of the stationary blade rows is referred to as “stationary blade clocking”.
[0005]
[Problems to be solved by the invention]
In the actual application of the stationary blade clocking, (1) the arrival position of the wake of the upstream stationary blade changes depending on the operating point, and (2) when the optimal position is set for the efficiency, the vibration of the moving blade may have an allowable value. There is a problem that it may be exceeded.
[0006]
In recent years, many literatures have reported the efficiency improvement effects of clocking in compressors and turbines of gas turbine engines (for example, Japanese Patent Application Laid-Open No. 9-512320, Japanese Patent Application Laid-Open No. 54-114618).
[0007]
These documents all state that the efficiency is optimum when the upstream stator blade wake hits the downstream stator blade leading edge. It is also known that the efficiency of the stationary blade clocking is maximized when the upstream stationary blade wake is placed at a circumferential position where the downstream stationary blade leading edge is covered. In addition, it has been reported that in many cases, the vibration level of the blades sandwiched therebetween increases when the efficiency is maximized.
[0008]
However, the conventional stationary blade clocking has the following problems.
(1) Particularly in an aeronautical gas turbine, the downstream direction of the upstream stationary vane wake also changes due to a change in the operating point, so that an optimal clocking effect cannot be obtained in all operating states, and a specific operating state The arrangement is set with. Therefore, the efficiency cannot be improved under other operating conditions.
(2) Depending on the circumferential arrangement due to clocking, the vibration level of the moving blades sandwiched between them may be excessive, and there are operating conditions where the vibration exceeds the allowable level in the arrangement that optimizes efficiency. obtain.
[0009]
The present invention has been made to solve such a problem. That is, an object of the present invention is to find the optimum position of the stationary blade clocking according to the change of the operating point and change it in real time, thereby always operating at a high efficiency and a vibration level which does not exceed an allowable level. And a position control method therefor.
[0010]
[Means for Solving the Problems]
According to the present invention, there is provided a stationary blade clocking device for a multi-stage axial flow turbine or a compressor, wherein the stationary blade row moving device moves a downstream stationary blade row (4) in a circumferential direction with respect to an upstream stationary blade row (2). (12), a leading edge total pressure sensor (14) embedded in the downstream stationary blade row (4) for measuring the total pressure of the leading edge, and a moving blade row (4) between the upstream stationary blade row and the downstream stationary blade row ( The vibration sensor (16) for measuring the vibration of 3), the stationary blade row moving device is controlled in accordance with the measured values of the leading edge total pressure sensor and the vibration sensor, and the downstream stationary blade row is moved to the optimal position in the circumferential direction. And a position control device (18).
[0011]
According to the configuration of the present invention, the downstream stationary blade row (4) is circumferentially moved relative to the upstream stationary blade row (2) by the stationary blade row moving device (12), and the leading edge total pressure sensor (14) is moved. To measure the total pressure of the leading edge portion embedded in the downstream stationary blade row (4), and to measure the vibration of the moving blade row (3) between the upstream stationary blade row and the downstream stationary blade row by the vibration sensor (16). be able to.
In addition, the position control device (18) controls the stationary blade row moving device (12) according to the measured values of the leading edge total pressure sensor (14) and the vibration sensor (16) to rotate the downstream stationary blade row (2). It can move to the optimal position in the direction.
[0012]
Further, according to the present invention, there is provided a position control method for a stator blade clocking of a multi-stage axial turbine or a compressor, wherein a downstream stator blade row (4) is circumferentially pitched relative to an upstream stator blade row (2). A scanning step (S1) for performing scanning for each minute, and a total pressure measuring step (S2) for measuring the total pressure of the leading edge of the downstream stationary blade row (4) during the scanning and detecting the minimum total pressure position (P1). A positioning step (S3) of moving the downstream stationary blade row (4) to the minimum total pressure position (P1); and a step of detecting a moving blade vibration level and comparing it with a predetermined allowable level (A1). A blade vibration comparing step (S4) and a downstream stationary blade row moving step (S5) of moving the downstream stationary blade row (4) circumferentially a predetermined distance when the moving blade vibration level exceeds a predetermined allowable level (A1). Steps (S4, S5) are performed at the rotor blade vibration level. Repeated until a predetermined tolerance level (A1) below, position control method of the vane clocking, characterized in that there is provided.
[0013]
According to this method, the total pressure is minimized at the center of the upstream stationary blade wake, so that the downstream stationary blade row positioning step (S3) moves to the minimum total pressure position (P1) detected in the total pressure measuring step (S2). By moving the row (4), the upstream stator vane wake can be maintained in an optimal state in which the downstream stator vane leading edge suffers.
[0014]
Therefore, if the moving blade vibration level at this position is equal to or lower than the predetermined allowable level (A1) in the moving blade vibration comparing step (S4), the downstream static position is the highest in efficiency and the vibration level is below the allowable level. The cascade (4) can be positioned.
[0015]
Also, even when the blade vibration level exceeds the predetermined allowable level (A1) at this position, the downstream stationary blade row (4) moves in the circumferential direction until the blade vibration level falls below the predetermined allowable level (A1). , The vibration level does not exceed the allowable level, and the downstream vane row (4) can be positioned at the position with the highest efficiency.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description is omitted.
[0017]
FIG. 1 is a configuration diagram of a stationary blade clocking device of the present invention. In this figure, the stationary blade clocking device of the present invention includes a stationary blade row moving device 12, a leading edge total pressure sensor 14, a vibration sensor 16, and a position control device 18. In this example, the stationary blade clocking device of the present invention is a stationary blade clocking device of a multi-stage compressor, but can also be applied to an axial flow turbine.
[0018]
The stationary blade row moving device 12 includes a gear 12a, a motor 12b, an actuator system 12c, and the like, and can move the downstream stationary blade row 4 in the circumferential direction with respect to the upstream stationary blade row 2.
The leading edge total pressure sensor 14 is embedded in a part of the stationary blades of the downstream stationary blade row 4, and measures the total pressure of the leading edge of the downstream stationary blade row 4.
The vibration sensor 16 is, for example, an optical vibration sensor attached to the casing wall, and measures the vibration of the moving blade row 3 between the upstream stationary blade row 2 and the downstream stationary blade row 4.
The position control device 18 controls the stationary blade row moving device 12 in accordance with the measured values of the leading edge total pressure sensor 14 and the vibration sensor 16 to move the downstream stationary blade row 4 to an optimal position in the circumferential direction.
[0019]
FIG. 2 is a schematic diagram of the position control method of the stationary blade clocking of the present invention, and FIG. 3 is a flowchart of the position control method of the stationary blade clocking of the present invention.
[0020]
As shown in FIG. 2 and FIG. 3, the position control method of the stationary blade clocking of the present invention is a position control method of the stationary blade clocking of the multi-stage axial turbine or the compressor, and includes a scan step (S1) and a total pressure measurement. Step (S2), downstream stationary blade row positioning step (S3), moving blade vibration comparison step (S4), and downstream stationary blade row moving step (S5).
[0021]
During operation, for example, when the operating point (speed, throttle) of the jet engine is changed (S0), the method of the present invention is started.
In the scan step (S1), the downstream stationary blade row 4 is scanned by the stationary blade row moving device 12 in the circumferential direction with respect to the upstream stationary blade row 2 by the pitch of the blade row.
During this scan, in the total pressure measurement step (S2), the total pressure at the leading edge of the downstream stationary blade row 4 is measured by the leading edge total pressure sensor 14 to detect the minimum total pressure position P1.
In the downstream stationary blade row positioning step (S3), the downstream stationary blade row 4 is moved to the already determined minimum total pressure position P1 by the stationary blade row moving device 12.
In the moving blade vibration comparison step (S4), the moving blade vibration level is detected by the vibration sensor 16 and compared with a predetermined allowable level A1. The predetermined allowable level A1 is determined within a range that does not hinder the operation of the jet engine or the like.
[0022]
If the moving blade vibration level exceeds the predetermined allowable level A1 in this comparison, in the downstream stationary blade row moving step (S5), the stationary blade row moving device 12 moves the downstream stationary blade row 4 in the circumferential direction by a predetermined distance ΔL. I do. This predetermined distance ΔL is about 1/100 to 1/10 of the pitch of the cascade.
Steps (S4, S5) are repeated until the rotor blade vibration level falls below the predetermined allowable level A1, and when it falls below the predetermined allowable level A1, a stationary blade position is determined at that position (S6).
[0023]
The vibration level of the moving blade may be monitored by the vibration sensor 16 in parallel between the scanning step (S1) and the downstream stationary blade row positioning step (S3), and may be stored in a memory or the like.
In this case, the moving direction in the downstream stationary blade row moving step (S5) may be determined based on the storage.
[0024]
FIG. 4 is an embodiment of the apparatus and method of the present invention. In this figure, the horizontal axis represents the movement position of the downstream leading edge with the cascade pitch being 100%, and the vertical axis represents the upstream blade wake, efficiency, and excitation force (moving blade vibration level).
From this figure, since the total pressure is minimum at the center of the upstream stationary blade wake, if the downstream stationary blade 4 is moved to this position P1, the upstream stationary blade wake is maintained in an optimal state in which the downstream stationary blade front edge is covered. We can see that we can do it.
At the same time, the vibration of the intermediate moving blade is monitored by a vibration sensor attached to the casing wall, and when the moving of the downstream stationary blade causes the blade vibration level to exceed an allowable level A1 previously set in the controller, It can be seen that, by finely moving the downstream stationary blade in the circumferential direction (P2, P3), the effect of improving the efficiency by clocking can be obtained under any operating condition and the blade can be prevented from being damaged due to excessive blade vibration.
[0025]
FIG. 5 is a diagram of a flow field corresponding to the embodiment of FIG. In this figure, (A), (B), (C), and (D) show the flow field at each clocking position at 0%, 25%, 50%, and 75%, respectively, with isentropic lines.
From this figure, it can be seen that at 25% of the position, the upstream blade wake collides with the downstream blade leading edge, and at the position P1 in FIG. Understand.
At the 75% position, the upstream blade wake passes between the downstream blades, so that the excitation force (rotor blade vibration level) is minimized in FIG. 4, but the efficiency is also minimized.
[0026]
According to the configuration of the present invention described above, the downstream stationary blade row 4 is moved in the circumferential direction with respect to the upstream stationary blade row 2 by the stationary blade row moving device 12, and is moved to the downstream stationary blade row 4 by the leading edge full pressure sensor 14. The total pressure of the embedded leading edge is measured, and the vibration of the moving blade row 3 between the upstream stationary blade row and the downstream stationary blade row can be measured by the vibration sensor 16.
Further, the position control device 18 controls the stationary blade row moving device 12 in accordance with the measured values of the leading edge total pressure sensor 14 and the vibration sensor 16 to move the downstream stationary blade row 2 to an optimal position in the circumferential direction. .
[0027]
In addition, according to the method of the present invention, since the total pressure is minimized at the center of the upstream stator vane wake, the downstream stator blade row positioning step (S3) reaches the minimum total pressure position P1 detected in the total pressure measurement step (S2). By moving the stationary blade row 4, the upstream stationary blade wake can be maintained in an optimum state in which the downstream stationary blade leading edge is covered.
[0028]
Therefore, if the moving blade vibration level at this position is equal to or lower than the predetermined allowable level A1 in the moving blade vibration comparing step (S4), the downstream stator blade row is located at the optimum position having the highest efficiency and the vibration level not exceeding the allowable level. 4 can be positioned.
[0029]
Further, even when the moving blade vibration level exceeds the predetermined allowable level A1 at this position, the moving blade vibration level moves in the downstream stationary blade row 4 in the circumferential direction by a predetermined distance until the moving blade vibration level becomes equal to or lower than the predetermined allowable level A1. In addition, the downstream stationary blade row 4 can be positioned at a position where the vibration level does not exceed the allowable level and has the highest efficiency.
[0030]
It should be noted that the present invention is not limited to the above-described embodiments and examples, and it is needless to say that various changes can be made without departing from the spirit of the present invention.
[0031]
【The invention's effect】
As described above, according to the present invention, (1) the optimum clocking position can be maintained at all the operating points within the allowable range of vibration, the efficiency can be improved, and (2) Operational safety can be secured by monitoring and suppressing in real time the increase in the blade vibration level due to clocking, which is difficult to predict in advance (at design time).
[0032]
Therefore, the stationary blade clocking device and the position control method of the present invention can find the optimal position of the stationary blade clocking according to the change of the operating point, and can change it in real time, thereby always having a high efficiency and an allowable level. It has excellent effects such as being able to operate at a vibration level that does not exceed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a stationary blade clocking device of the present invention.
FIG. 2 is a schematic diagram of a position control method for stationary blade clocking according to the present invention.
FIG. 3 is a flowchart of a position control method for stationary blade clocking of the present invention.
FIG. 4 is an embodiment of the apparatus and method of the present invention.
FIG. 5 is a diagram of a flow field corresponding to the embodiment of FIG. 4;
FIG. 6 is a configuration diagram of a conventional jet engine.
[Explanation of symbols]
2 upstream stator row, 3 rotor row, 4 downstream stator row,
12 stationary row moving device, 14 leading edge total pressure sensor,
16 vibration sensor, 18 position control device,
51 aircraft engines (jet engines),
52 fans, 53 compressors, 54 combustors,
55 turbines, 56 afterburners,
57 frame holder (flame holder),
58 fuel nozzle, 59 spark plug,
60 outer duct, 61 liner,
62 exhaust nozzle

Claims (2)

A multi-stage axial turbine or compressor stationary blade clocking device,
A stationary blade row moving device (12) for moving the downstream stationary blade row (4) in the circumferential direction with respect to the upstream stationary blade row (2), and a total pressure of the leading edge embedded in the downstream stationary blade row (4). A leading edge total pressure sensor (14) for measuring, a vibration sensor (16) for measuring vibration of a moving blade row (3) between an upstream stationary blade row and a downstream stationary blade row, a leading edge full pressure sensor and a vibration sensor And a position control device (18) for controlling the stationary blade row moving device in accordance with the measured value of (i) and moving the downstream stationary blade row to an optimal position in the circumferential direction. A position control method for a stationary blade clocking of a multistage axial turbine or a compressor,
A scanning step (S1) of scanning the downstream stator blade row (4) in the circumferential direction by the blade row pitch with respect to the upstream stator blade row (2);
A total pressure measuring step (S2) of measuring the total pressure at the leading edge of the downstream stationary blade row (4) during the scan and detecting a minimum total pressure position (P1);
A downstream stator row positioning step (S3) for moving the downstream stator row (4) to the minimum total pressure position (P1);
A blade vibration comparing step (S4) for detecting the blade vibration level and comparing it with a predetermined allowable level (A1);
A downstream stationary blade row moving step (S5) for moving the downstream stationary blade row (4) in the circumferential direction by a predetermined distance when the moving blade vibration level exceeds a predetermined allowable level (A1);
A step control method for stationary blade clocking, characterized by repeating steps (S4, S5) until the rotor blade vibration level falls below a predetermined allowable level (A1).

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