JPS5981532A - Abnormality diagnosing device for diaphragm coupling of shaft system - Google Patents

Abstract

PURPOSE:To diagnose abnormality of the diaphragm of a diaphragm coupling accurately, and to control the operation condition of respective equipments of a shaft system and improve the safety of the shaft system, by providing a detecting means at a gap part formed between the diaphragm and the coupling. CONSTITUTION:The detecting means 103 which detects the amount of variation due to the displacement of the diaphragm 14 is provided at the gap part 32 between the diaphragm 14 of the diaphragm coupling 102 and a coupling base 11. The detecting means 103 consists of a displacement gauge 21 which measures the relative axial displacement between the diaphragm 14 and coupling boss 11 and a transmitter 22. A displacement signal is inputted to a comparative judging means 105 through an arithmetic means 104, and compared with a predetermined value; and an operation control means 106 performs operation control, such as a load decrease, rotating speed decrease, and turbine tripping, over respective equipments. The amount of variation at the gap part 32 is detected directly, so the resonance state of the diaphragm 14 is detected accurately and speedily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an abnormality diagnosis device for a diaphragm coupling in an axle thread, and in particular, the present invention relates to an abnormality diagnosis device for a diaphragm coupling in an axle thread. The present invention relates to an abnormality diagnosing device for a diaphragm coupling on a side 1 system and 2, which diagnoses an abnormality in a diaphragm coupling provided between the shafts of a combined cycle plant located above, and controls the operating conditions of each of the above-mentioned devices.

[Prior art]

As a power generation plant that is highly efficient and can respond to peak loads, a combined cycle plant consisting of a compressor, a gas turbine generator, and a steam turbine (with the table equipment placed on -111I+) is effective. During operation of this joint cycle plant, the gluing and rotor shafts of each of the above-mentioned equipment expand thermally, and due to the difference in expansion, the spaces between the above-mentioned equipment become clogged, and the shafts between each equipment expand. In order to prevent the occurrence of this stress, a flexible joint 1 is provided between the devices and absorbs the stress by its flexure.The flexible joint is a diaphragm cup having a diaphragm. The diaphragm of the diaphragm coupling is subjected to various stresses such as tension, compression and bending during operation. The diaphragm may be damaged due to this force and resonance, causing the diaphragm coupling to fly off, which is extremely dangerous. Conventionally, abnormality diagnosis devices have been used to prevent this.One of these devices is one in which stress measuring means such as a strain gauge is attached directly to the diaphragm, and the other is in which a strain gauge is attached to the shaft of the diaphragm coupling. For measuring the displacement on the coupling side of the shaft system where the diaphragm coupling straddles, etc.
1. A device is used to monitor the vibration state of the yaphram coupling. However, both methods have the disadvantage that it is difficult to accurately and directly determine the abnormality of the diaphragm, and in particular, it is difficult to determine the resonance state of the diaphragm.

That is, as shown in FIG. 1, a combined cycle plant 1
00 consists of a compressor 1, a gas turbine 2, a generator 3, and a steam turbine 4, which are supported by a radial bearing 9 on one shaft 101 and arranged in series. Pressure machine 1
A thrust bearing A7 is provided at one end 11111 to restrict thermal expansion in this direction. One end side of a gas turbine 2 is connected to the other end side of the compressor 1, and one end side of a generator 3 is connected to the other end side of the gas turbine 2 via a thrust bearing B5. Therefore, the compressor 1, the gas turbine 2, and the generator 3 thermally expand toward the other end of the generator 3, that is, one end of the steam turbine 4, starting from the thrust bearing A7.

Due to the high temperature of the gas turbine 2, the elongation due to this thermal expansion is 30 m/m to 4 m/m between the cold state and the steady operation state.
5m/m; reaches i degree. Therefore, if the absorption means for absorbing this elongation and the thrust bearing C8 that regulates the effect of the elongation on the steam turbine 4 side are provided between the other end side of the generator 3 and one end side of the steam turbine 4, the above elongation This directly acts on the steam turbine 4 and has a very negative effect on maintaining the performance of the steam turbine 4. A diaphragm coupling 6 has conventionally been generally employed as this absorption means.

As shown in Fig. 2, diaphragm coupling 1()2
is installed between the coupling boss 11 of the bearing 101 that is fitted onto the rotor shaft 16 of the generator 3 and the coupling boss 11 that is fitted onto the rotor shaft 10 of the steam turbine 4 . A diaphragm 14 having a weak spring constant in the axial direction is provided at both ends of the sleeve 15, and the outer peripheral side of the diaphragm 14 is connected to the square surface of the coupling boss 11 and the side surface of the compulsory cover 12 via the bolt 13. being held in place. Furthermore, a gap 32, which is a minute space, is formed between the diaphragm 14 and the coupling boss 11 at 4111.

As shown in FIG. 3(a), the diaphragm couplings 102 held at intervals absorb the difference in elongation X caused by thermal expansion, etc., and the diaphragm 14 deforms as shown in FIG. 3(b). , the pressing interval I in the axial direction, -
It is held at X. Furthermore, when the axis is deviated by a displacement δ, the diaphragm 14 is torsionally deformed and absorbs the displacement δ while maintaining the spacing as shown in FIG. 3(C). Therefore, in each figure of Figure 3, the center line V is indicated by a dashed line, and the hatching indicating the cross section is omitted.)
. Further, in the shaft system 101, a large elongation occurs in the axial direction as described in "2", but the displacement of the shaft center is usually a small value of about ±0.5. Therefore, the diaphragm 14 is formed to have extremely low axial rigidity.

As described above, the diaphragm coupling 102 allows
Although the elongation and displacement of the shaft system are absorbed, as mentioned above, the diaphragm 14 is subjected to displacement due to the excessive elongation difference X, torsion due to the displacement δ, centrifugal force due to high rotation, etc.
Careless stress is applied. Due to the action of this stress, if the diaphragm 14 is damaged during operation, not only will the diaphragm coupling 102 be scattered, but the parts around the rotor shaft 16 of the generator 3 and the rotor shaft 10 of the steam turbine 4 will be damaged. A devastating accident occurs in which these particles are scattered.Therefore, it is necessary to diagnose the abnormality of the diaphragm 14 and maintain the safety of the ΦJIl system.

For this reason, various abnormality diagnosis devices have been employed in the past as well.

As one of the devices, as shown in FIG. 4, a strain gauge 17 is directly attached to the surface of the diaphragm 14, and the amount of strain is transmitted from a transmitter 20 such as a telemeter system, and is transmitted by a receiver, an arithmetic unit, etc. (not shown). There are devices that measure that stress. However, since the diaphragm coupling 102 normally rotates at a high rotation speed of 3000 rpm or more, an extremely large centrifugal acceleration acts on the diaphragm 14, making it difficult to securely bond and hold the φ gauge 17 on the surface of the diaphragm 14. It had Also, as shown in FIG. 4, a diaphragm coupling 102
A device is also adopted in which a strain gauge 18 is attached to the outer periphery of the sleeve 15, and a transmitter 19 transmits a detected value of the strain amount. In addition, as shown in FIG. 5, detectors A41 and B42 for detecting the amount of displacement in the axial direction are provided at the 7 flange portions of the cambling bosses 11 on both sides that are joined to the diaphragm coupling 102. A detector C40 for measuring the displacement phase in the axial direction is provided on the flange portion on the opposite side of the The detection signal of the device C40 is input to the telescopic display 45 to clearly indicate the displacement in the axial direction. In this case, the operator should check the eccentricity indicator 44 and the telescopic indicator 45.
The operator reads the display on the rotational speed indicator 46, load indicator 47, etc. provided on the shaft system, and adjusts the shaft system based on his/her own judgment.

4 and 5 are effective to some extent as a device for diagnosing abnormalities in the diaphragm 14. However, as mentioned above, the diaphragm 14
The spring constant in the axial direction is extremely low, and the primary natural frequency in the axial direction is between 1500 ffJm and 2000 rpm. Therefore, when the shaft system is operated at half of its rated rotational speed of 3000 rμ or 36001 rpm, there will be a case where the rotational speed of the shaft system almost coincides with the natural frequency of the diaphragm. On the other hand, shaft system illusion: Because the rotation speed is temporarily maintained at around half the rated rotation, resonance of the diaphragm 14 occurs during operation.
This may cause the diaphragm 14 to be damaged. Each of the above devices has the drawback that it is difficult to accurately grasp the resonance state of the diaphragm 14.

[Purpose of the invention]

The present invention has been devised to solve the above-mentioned drawbacks.The purpose of the present invention is to accurately diagnose abnormalities in the diaphragm, and control the operating conditions of each shaft system device based on the diagnostic results. In addition to improving system safety and reliability,
An object of the present invention is to provide an abnormality diagnosis device for a diaphragm coupling in a shaft system, which has a simple structure.

[Summary of the invention]

In order to achieve the object of the present invention, a detection means is engaged in a gap formed between a diaphragm of a diaphragm coupling and a coupling connected oppositely to the diaphragm, and Detects changes such as relative axial displacement, pressure fluctuation, sound fluctuation, and temperature change that occur in the gap,
This change value is input to the comparison and judgment means via the calculation means, and compared and judged with a predetermined set value, and based on the results, the operation conditions of each shaft thread device are controlled by the operation control means. The present invention is characterized by an abnormality diagnosis device fl for a diaphragm coupling in a shaft system that accurately determines abnormalities such as resonance of the diaphragm and improves the safety and reliability of the shaft system.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be explained based on the drawings. , reveal.

First, an overview of this embodiment will be explained.

6, 8, and 9, the gap portion of the minute space formed between the diaphragm 14 of the diaphragm coupling 102 and the coupling boss 11 oppositely joined to the diaphragm 14 At 32? 2j: Detecting means 103 is provided for detecting the amount of change that occurs in the gap 32 due to the displacement of the diaphragm 14. For example, the sixth
The detection means 103 in the figure is composed of a displacement meter 21 that measures the relative axial displacement between the diaphragm 14 and the coupling boss 11, and a transmitter 22 that transmits the displacement. As shown in FIGS. 7 and 10, the detection means 10
The displacement signal 12 from 3 is input to the calculation means 104, where calculations are performed for comparison with the set value input to the comparison and judgment means 105. This calculated value is the comparison judgment means 1
05, and is compared with a predetermined setting value and judged. As a result of this comparison and determination, the signal is input to the operation control means 106. The operation control means 106 controls the compressor 1
, operation controllers 28a, 28b, 28C that control the operation of the gas turbine 2, the generator 3, and the steam turbine 4.
and 28d, etc., and the above-mentioned signals are used to control the operation of the equipment, such as reducing the load, reducing the rotation speed, and tripping the turbine.

Since the detection means 103 described above directly detects the amount of change in the gap 32 adjacent to the diaphragm 14, it can accurately and quickly detect the above-mentioned resonance state of the diaphragm 14, and quickly diagnose abnormalities in the diaphragm 14. I can do it.

Next, this embodiment will be explained in more detail.

As shown in FIG. 6, a detection means 1 is provided on the end surface of the rotor shaft 16 on the gap 32 side into which the coupling boss 11 is inserted.
A displacement gauge 21, which is one of the components of 03, is provided on the diaphragm 14 in a non-contact manner. Since this displacement meter 21 is provided close to the diaphragm 14, it is possible to directly and accurately grasp the displacement of the diaphragm 14.

Of course, since the rotor shaft 16 is also displaced in the axial direction, the displacement meter 2
1 will measure the relative axial displacement of the diaphragm 14. Near the displacement meter 21 on the end face of the rotor shaft 16,
A telemeter type transmitter 22 is provided 7'11, a displacement meter 2
A displacement signal based on 1 is transmitted to the outside.

The calculating means 104 is provided on the outside of the shaft system, and is composed of a receiver 23, a calculating unit A24, a calculating unit 825, etc., as shown in FIG. The displacement signal is received by the receiver 23, is converted into a displacement amount by the calculator A24, and is converted into a displacement amount by the calculator B2.
5, the relative vibration amplitude value of the coupling 14 is calculated.

As shown in FIG. 7, the comparison and judgment means 105 is installed outside the shaft system. It consists of a comparator 26 and a judge 27.

Predetermined set values are input to the comparator 26 and the judge 27. This setting value is the power of the above calculation unit 825.
It is established from vibration amplitude values of the same type as the relative vibration amplitude values output from Further, as the set value, either an obituary value for warning of an abnormality in the shaft system or a tolerance value for allowing the safety of the shaft system is adopted.

The relative vibration amplitude value from the calculator B25 is compared with the width value of the set value by the comparator 26, and the result is input to the 65 judger 27. The judge 27 sends a signal to the operation control means 106 when the relative vibration amplitude value exceeds the above-mentioned threshold value or tolerance value.

The operation controller 28a of the sub-operation side j means 106 is engaged with the compression 128a, as shown in FIG.

Further, the operation controller 28b connects the gas turbine 2 to the operation controller 2.
8C is the generator 3, and the operation controller 28d is the steam turbine 4.
It is 1.2. These operation controllers 2
8a, etc. (Ij-1J: Comparison, Judgment means 105 A, Bow number, reduce the output load, throttle the input side to reduce the rotation speed, trip the turbine, stop the equipment, etc. It acts to avoid abnormalities in the diaphragm 14.

The permissible value of the above vibration amplitude value is determined by adding a safety factor to the fatigue limit stress of the diaphragm 14, and also taking into account the displacement of other shaft centers, the stress due to the difference in flange elongation due to centrifugal force, etc. It will be done.

FIG. 8 shows another ash embodiment, in which the gap 3 is used as the detection means 103.
This method employs the second method of detecting pressure fluctuations. That is, a pressure sensor 29 is provided at almost the same position as the displacement meter 21 shown in FIG. 6, and a transmitter 30 is located near it.
is provided.

Further, the end of the sleeve 15 on the gap 32 side to which the tanyaphragm 14 is attached is closed by a lid 48, and
An orifice 31 communicating with the inside of the sleeve 15 and the gap 32 is formed in the lid 48 .

When the diaphragm 14 vibrates, the pressure in the gap 32 fluctuates. Therefore, by measuring this pressure fluctuation value with the pressure sensor 29, the relative vibration amplitude of the diaphragm 14 can be determined in the same manner as described above. i.e. pressure) &
A moving image signal is transmitted from the transmitter 30, and as shown in FIGS.
As shown in FIG.
, acts on the operation control means 106.

The orifice 3] is for squeezing the air in the gap 32 and letting it escape into the sleeve 31, so that the pressure fluctuation value can be measured more accurately.

Further, as shown in FIG. 8, the pressure fluctuation value can be similarly determined from the pressure fluctuation in the gap A33. That is, when the inner circumferential side of the diaphragm cover 12 joined to the outer circumferential side of the outer circumferential side mating diaphragm 14 is brought close to the outer circumferential portion of the sleeve 15 via the minute air passage 34 and inserted, the diaphragm cover 12 and A gap A33 is also formed between the diaphragm 14 and the diaphragm 14.

The same effect can be achieved by detecting the pressure fluctuation value in the gap A33 in the same manner as above.

The ninth example shows still another embodiment, in which the detection means 10
3 is for detecting fluctuations in sound.

A sonic wave generator 35 is provided in a lid 48A that closes the end of the sleeve 15. This sonic generator 35 is formed of orifice-like passages 49 and 50 that communicate with the gap 32 and the sleeve 15, and an air chamber 51 that communicates with these passages 49 and 50, and responds to pressure fluctuations in the gap 32. It has the role of a whistle that generates a sound.

The external microphone 36 is installed on the outside of the diaphragm coupling 102 and catches the sound of the sound wave generator 35.

The displacement of the diaphragm 14 can be detected by the detection means 103 composed of the sonic wave generator 35 and the external microphone 36, and the displacement of the diaphragm 14 can be detected as in the above embodiment.
Can diagnose abnormalities. This embodiment does not require the use of a transmitter such as a telemeter, so it can be manufactured at low cost and easily.

In addition to the above, although not clearly shown in the figure, the detection means 103 detects temperature changes in the gap 32, gap A33, etc.
Means for diagnosing abnormalities in the diaphragm 14 may also be mentioned.

That is, due to the displacement of the diaphragm 14, 1. The air temperature around it increases. This is done by detecting this temperature change using a temperature sensor or the like. In this case, the operation control means 106 may be immediately controlled based on the increased temperature value without requiring the calculating means 104 to calculate the percentage.

Next, as shown in FIG. 11, by plotting the rotational speed N of the shaft system on the horizontal axis and the vibration amplitude on the vertical axis, a histogram of the vibration amplitude is obtained, and the natural frequency of the diaphragm 14 is The maximum vibration amplitude, , 1, occurs at point P at the corresponding rotational speed N, and this '! The vibration amplitude decreases as the rotational speed N increases and decreases around '1-.

Using this relationship, as shown in FIG. 12, the planned vibration amplitude flED for each rotation speed N is input to the comparator 26 of the comparing and determining means 105. That is, the rotational speed N of the shaft system is calculated by the tachometer 37 to a total of 1f (IIL), and this measurement signal is input to the vibration amplitude calculator 38 and the comparator 26.The planned vibration amplitude calculator 38 is based on FIG. A vibration amplitude value corresponding to the rotation speed N is inputted to the comparator 26.Comparator 26
Then, the vibration amplitude value inputted from the calculator B25 is compared with the planned vibration amplitude value at the pongee yarn rotation speed, and the result is inputted to the judgment device.

As described above, it is possible to diagnose an abnormality of the coupling according to the rotation speed, and the accuracy of the abnormality diagnosis can be further improved. Furthermore, a frequency analysis function is added to the computing unit B26, and the comparator 26 compares the vibration amplitude value actually measured for each rotation speed with the planned vibration amplitude value by the planned vibration amplitude computing unit 38, and detects abnormalities. In addition to diagnosing the problem, if there is a rotation speed at which an abnormal amplitude occurs, an alarm is issued and the operation control means 10
6 controls the operation of the shaft system. Thereby, the accuracy of abnormality diagnosis can be further improved.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to accurately diagnose abnormalities in the diaphragm, control the operation of the axle thread based on the diagnosis results, and improve the safety and reliability of the shaft system. The advantage is that the structure is simple and inexpensive.

[Brief explanation of drawings]

Figure 1 is a block diagram of a containment cycle plant, Figure 2 ('i
Section 9 showing the configuration of the diaphragm coupling, No. 3
Figures (a) to C) are explanatory diagrams showing the operation of the diaphragm coupling, Figure 4 is a perspective view showing the prior art, and Figure 5 is an explanatory diagram showing the operation of the diaphragm coupling.
The figures are the same (a cross-sectional view and a side view showing the prior art, FIG. 6 is a cross-sectional view showing one embodiment of the present invention, FIG. 7 is a block diagram explaining the operation of one embodiment, and FIG. 8 is a cross-sectional view showing the prior art). 9 is a sectional view showing another embodiment of the present invention, FIG. 10 is a configuration diagram explaining shaft system control of the embodiment, and FIG. 11 is a diagram showing the relationship between the rotation speed of the shaft system and vibration amplitude. FIG. 12 is a block diagram illustrating the operation of the embodiment. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Gas turbine, 3... Generator, 4... Steam turbine, 6,102... Diaphragm coupling, 10.16... Rotor shaft, 12...
...Coupling cover, 13...Bolt, 14...
Diaphragm, 15... Sleeve, 21... Displacement meter, 22... Transmitter, 23... Receiver, 24... Arithmetic unit A125... Arithmetic unit B. 26...Comparator, 27...Judgment device, 28a, 2
8b. 28C, 28d... Operation controller, 29... Pressure sensor, 30-11 transmitter, 31... Orifice, 32...
...Gap q s, 33001 Gap A134... Air passage, 35... Sound wave generator, 36..., External microphone, 3
7... times kgl-s 38... Planned vibration amplitude calculator, 48, 48A... Bad, 49°50019 passage, 5
1 Air chamber, 03-, Detection means, 104... Calculation, 105... Comparison, judgment means, 106... Operation shouting means. Agent Patent Attorney Masami Akimoto S Figure 1z Otsu Nagamachi 12 Figure 7 o5 Bian 9th Zugo 10 Zutaku 117 No. 121

Claims (1)

[Scope of Claims] 1゜ A 1ljill system having diaphragms that are disposed across couplings of IIIll threads having respective Yuzu devices and that face each other across a gap portion forming a minute space from the 111 plane for campling. In the abnormality diagnosis device for a diaphragm coupling, a detection means detects a change value occurring in the gap due to displacement of the diaphragm, and a comparison and judgment means compares and judges the change value and a preset setting value. , an effect means for applying the change value to the comparison and judgment means, and each 8! of the upper six self-axis systems based on the results of the comparison and judgment means V. An abnormality diagnosis device for a diaphragm coupling in a shaft system, characterized in that it is equipped with a driving side means for controlling the operating conditions of the equipment. 2. An abnormality diagnosis device for a diaphragm coupling on the shaft 1 according to claim 1, wherein the change value is a relative axial displacement between the side surface of the coupling and the diaphragm. 3. An abnormality diagnosis device for a diaphragm coupling in an axoneme according to claim 1, wherein the change value is a pressure fluctuation value within the gap. 4. Abnormality diagnosis of a diaphragm coupling in a shaft system according to claim 1, wherein the change value is a value obtained by converting a pressure fluctuation value occurring in the gap into a sound fluctuation value. Device. 5. An abnormality diagnosis device for a diaphragm coupling in a shaft system according to item 1, wherein the change value is a change in hot water temperature occurring in the gap. 6. The calculation means calculates changes such as relative axial displacement, pressure fluctuation value, and sound fluctuation value detected by the detection means to convert them into relative vibration amplitude between the coupling and the diaphragm. An abnormality diagnosis device for a diaphragm coupling in a shaft system according to any one of claims 2, 3, and 4. 7. Relative axial displacement and pressure fluctuation by the detection means
! Claims 2, 3, and 3 are characterized in that the amount of change in the noise and the fluctuation value of the sound is detected in correspondence with the rotational speed of the diaphragm coupling of the shaft system. An abnormality diagnosis device for a diaphragm coupling in a shaft system according to any one of Items 4 to 4. 8. The diaphragm cup in the shaft system according to item 1, wherein the set value is an alarm value that warns of abnormality in the shaft system or an allowable value that maintains the safety of the shaft system. Ring pseudonym diagnostic device. 96. The shaft system according to claim 1, wherein the operation control means controls the operation of various devices of the shaft system, such as reducing the load, reducing the rotation speed, and tripping the turbine. Abnormality diagnosis device for diaphragm couplings.