JPS6212845B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vibration measuring device for a rotating body in a high-temperature atmosphere, and in particular, to eliminate vibration value deviations due to changes in the minute gap between a vibration detector and the rotating body due to high temperatures. This invention relates to a vibration measuring device in a high-temperature atmosphere.

Conventionally, there have been relatively few devices for measuring vibrations of rotating bodies in high-temperature atmospheres. This is because measurement in a high-temperature atmosphere is technically difficult. In other words, high-quality detectors used in high-temperature atmospheres have characteristics that are almost the same as those used at room temperature. This is because it is extremely difficult to maintain a constant value. This is because the holder that holds the detector and the main body to which this holder is attached expand or deform due to heat, thereby changing the minute gap. FIG. 1 shows the detector characteristics representing the relationship between the gap between the vibration detector and the object to be measured and the potential difference. The horizontal axis δ represents the gap, and the vertical axis V represents the potential difference. In the figure, the gap δ and the potential difference maintain a linear relationship up to a value of about 1 m/m.
Even in very special cases, the limit is about 2m/m (not shown). Therefore, in order to measure the vibration of a rotating body, it is necessary to detect the gap change within the above-mentioned minute gap, and therefore it is difficult to perform accurate vibration measurements in a high temperature atmosphere with large thermal expansion. was considered a virtually impossible technology.

The present invention was proposed to solve the above technical difficulties, and its purpose is to maintain a constant gap between the vibration detector and the object to be measured even in a high-temperature atmosphere, and to prevent abnormal changes in the gap. It is an object of the present invention to provide a vibration measuring device in a high temperature atmosphere suitable for performing accurate vibration measurements by catching and controlling the vibrations in advance.

In order to achieve the above object, the present invention includes a drive unit that places a vibration detector close to a rotating body and adjusts a minute gap, a gap detector that is disposed near the vibration detector of the drive unit, and A vibration measuring device in a high-temperature atmosphere comprising a sliding detector, a control device that controls the drive device based on detection signals from these, and a cooling device that cools the drive device section. It is.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 2, the vibration measuring device includes a rod 7 to which a vibration detector 13 is attached, a traverse device 5 that incorporates a pulse motor 6, etc., a cooling device (not shown) that cools the inside of the traverse device. and a control device 31. Outer wall 1 of a turbine casing containing a turbine rotor 16
A heat insulating material 2 is coated on the outside. The traverse device 5 is provided on the outside of the turbine casing.
It is attached via legs 3 and flanges 4. At the tip of the rod 7 built into the traverse device 5,
A vibration detector 13 is attached, and the vibration detector 13
is arranged at a position separated from the outer periphery of the turbine rotor by a minute gap δ. The rod 7 is suspended vertically in the figure by an upper support plate 11 and a lower support plate. The piece 10 is inserted into the rod 7, and the piece 10 is fixed to the rod 7 with a screw 10a.A screw hole 9 is formed in the piece 10 parallel to the hole into which the rod 7 is inserted. A pulse motor shaft 8 is screwed in parallel with the motor 7. The pulse motor shaft 8 is attached to the upper support plate 1
It is fixed to a pulse motor 6 attached to 1.
A gap detector 14 is attached to the tip of the rod 7 near and parallel to the vibration detector 13. Both the gap detector 14 and the turbine rotor 16 are arranged with a minute gap δ separating them. Rod 7
A sliding detector 15 is further attached to the tip. Note that the sliding detector 15 is arranged closer to the turbine rotor 16 by a dimension a than the vibration detector 13 and the like. The vibration detector 13 , the gap detector 14 , and the sliding detector 15 are each connected to the control device 31 and send detection signals to the control device 31 . A cooling device (not shown) is connected to the traverse device 5, and the cooling air 18 enters the inside of the traverse device 5 from the inlet 19, cools each component, and then flows to the outlet 2.
Discharge from 0. As mentioned above, the traverse device 5 is placed outside the turbine casing outer wall 1 via the heat insulating material 2, but the temperature becomes quite high, which adversely affects the lubrication of the built-in pulse motor 6 and each drive section. , the cooling device will work effectively.

Next, the automatic traverse system with the above configuration will be explained with reference to FIG. The detection signal from the gap detector 14 is amplified by an amplifier 21 and then enters a bandpass filter 22 . Signal a output from bandpass filter 22
passes through the AD converter 23 and is converted into a digital signal b. Digital signal b is temporarily stored in digital memory (or delay circuit) 24. The digital signal c output from the digital memory 24 enters the signal generator 25. A reference value signal from a reference value setter 26 is sent to the signal generator 25, and after comparing the digital signal c and the reference value signal, the signal is sent to a switch 27. That is, gap detector 1
If the gap δ between 4 and the turbine rotor 16 is larger than the preset reference value D ₀ , the gap δ
The signal generator 25 generates a signal for moving the gap δ in the direction of narrowing it, or in the opposite case, widening the gap δ, and sends this signal to the switch 27. switch 2
Reference numeral 7 denotes an open/close switch which sends a signal sent by the timer 28 to the pulse motor 6 only for a preset minute period of time. As the pulse motor 6 rotates, the rod 7 moves up and down as shown in FIG. 1, thereby adjusting the gap δ. As described above, the vibration detector 13 can accurately measure vibrations while maintaining an appropriate gap based on the gap δ controlled by the gap detector 14.

Next, as described above, the sliding detector 15 is arranged on the turbine rotor 1 by a dimension a larger than the vibration detector 13 and the like.
6, the vibration detector 13
sliding detector 1 before contacting the turbine rotor.
5 will be in contact. With this warning means,
The danger of the vibration detector 13 and the like coming into contact with the turbine rotor 16 is prevented in advance.

Since the gap detector 14 normally uses an eddy current type gap sensor, there is a zero drift, and an error occurs in the absolute value of the gap, especially when used for a long time. Therefore, a system method for preventing the above-mentioned error in the gap detector 14 and preventing damage to the vibration detector 13 and the like from contact with the turbine rotor 16 is shown in FIG. In the figure, the same numbers and symbols as in FIG. 3 represent the same parts and functions.
The electrical signal from the sliding detector 15 is sent to a calculator 29, which calculates the degree of signal change ΔT within a minute time Δt, that is, ΔT/Δt. A preset reference value of ΔT/Δt is sent to the calculator 29 from the reference value setter 30. This reference value and the above calculated value ΔT/Δ
t is compared, and if it exceeds the reference value, the arithmetic unit 29
The electric signal from the pulse motor 6 is controlled to directly act on the signal generator 25 to move the pulse motor 6 in the direction of widening the gap δ.

In the above embodiment, the traverse device 5 has a structure that operates to automatically adjust the gap between the vibration detectors 13 based on the detection signal, but the gap adjustment between the vibration detectors 13 is limited to an automatic method. Without,
The gap may be adjusted manually based on an abnormal signal from a vibration detector.

As is clear from the above description, according to the present invention, even in a high-temperature atmosphere, by controlling the gap between the vibration detectors to an appropriate size, the linear range of the vibration characteristics of the gap sensor is approximately 1 m/m. Even in narrow spaces, it is possible to accurately measure vibrations over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the gap characteristics of the vibration detector;
FIG. 2 is a sectional view showing the main parts of a vibration measuring device according to an embodiment of the present invention, FIG. 3 is a block diagram showing a measurement system system according to an embodiment of the present invention, and FIG. 1 is a block diagram showing a system for protecting a vibration measurement sensor according to an embodiment of the present invention; FIG. DESCRIPTION OF SYMBOLS 1... Turbine casing outer wall, 5... Traverse device, 6... Pulse motor, 7... Rod,
13... Vibration detector, 14... Gap detector, 15
...Sliding detector, 16...Turbine rotor, 18
...Cooling air, 21...Amplifier, 22...Band filter, 23...AD converter, 24...Digital memory, 25...Signal generator, 26, 30...Reference value setter, 27... ...Switch, 28...Timer, 29...Arithmetic unit, 31...Control device.

Claims (1)

[Scope of Claims] 1. A drive for driving a vibration detector in a vibration measuring device in a high temperature atmosphere that measures the vibration of a rotating body based on changes in the minute gap between the rotating body and the vibration detector in a high temperature atmosphere. a device section, a gap detector disposed near the vibration detector position of the drive device section to detect a change in the minute gap, and a drive device such as the vibration detector that responds to a detection signal of the gap detector. The device is placed near a control device unit that operates the drive unit and a vibration detector, etc. of the drive device unit, at a position having a gap smaller than a minute gap of the vibration detector, etc., and detects changes in the gap. A high-temperature device comprising: a sliding detector for detecting a sliding motion; a control device for operating the driving device in response to a detection signal from the sliding detector; and a cooling device for cooling the driving device. Vibration measuring device in atmosphere. 2. The drive unit according to claim 1 moves a rotation mechanism unit that rotates in response to a detection signal from a gap detector, a vibration detector, etc. in a direction toward or away from the rotating body. A vibration measuring device in a high-temperature atmosphere, comprising a drive mechanism section. 3. The control device section according to claim 1 is capable of detecting a temporal change in the detection signal by the sliding detector,
A vibration measuring device in a high temperature atmosphere, characterized in that the vibration measuring device is configured to operate the drive unit when a predetermined level value is exceeded. 4. In a high temperature atmosphere, the control device section according to claim 1 has an alarm device that issues an alarm when the gap between the sliding detector and the rotating body becomes less than a predetermined gap. vibration measuring device. 5. The cooling device according to claim 1,
A vibration measuring device in a high-temperature atmosphere, comprising a cooling fluid that circulates through the drive unit.