JPS62215841A - Apparatus for monitoring axis of rotary machine - Google Patents

Abstract

PURPOSE:To make it possible to monitor the eccentric degree of an axis, by arranging pressure detectors at a plurality places on the circumference of the seal provided to a rotary machine and mounting an apparatus for measuring the pressure distribution on the circumference on the detection outputs from said detectors and an apparatus for converting the position of the axis from said pressure distribution. CONSTITUTION:A pressure detector is constituted of a measuring hole 15, a pressure guide pipe 10 and a pressure converter 17. As a means for measuring the eccentricity of the axis of a rotary machine, a plurality (four in a drawing) of measuring holes 15 are provided on the internal circumferences of seals A, B, C and guided to the pressure converters 17 by the pressure guide pipes 16 and the pressures in the seals A, B, C are calculated to calculate pressure distribution by a measuring apparatus 18. This pressure distribution is converted to the axis position from the relation between the seal eccentricity and pressure distribution preliminarily inspected by an axis position converter 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device for measuring and monitoring the degree of eccentricity of the axis of a rotating machine, and is applicable to steam turbines, gas turbines, axial flow compressors, centrifugal compressors, pumps, and water turbines. It can be used for etc.

2. Description of the Related Art As an example of a conventional rotary machine, a centrifugal compressor is shown in FIGS. 5 and 6. In the figure, 1 is a steam inlet, 2 is a nozzle, 3 is a moving blade, 4 is a disk, 5 is a thrust bearing, 9 is a casing, 10 is a high pressure section, 11 is a low pressure section, 12 is a gas inlet, and 13 is an impeller. , 14 are gas outlets, and A, B, and C are seals.

In the centrifugal compressors shown in Figs. 5 and 6, in order to measure and monitor the degree of eccentricity of the shaft center, a gap sensor (displacement measuring device) is installed near the bearing 7, and the eccentricity of the shaft center is determined from the output of these sensors. I had no choice but to estimate the degree. Providing this gap sensor inside the casing 9 has problems in terms of heat resistance and pressure resistance.

Problems to be Solved by the Invention The degree of eccentricity of the shaft center should always be monitored in an appropriate manner, since excessive eccentricity of the rotating shaft causes inconveniences such as vibrations caused by contact and increased seal leakage due to wear. This arises from the need to set the shaft center in position, and in particular, the present invention has the following advantages in rotating machinery: (a) It is highly reliable even in high-temperature and high-pressure parts, and (b) It does not require expensive sensors. (c) It is an object of the present invention to provide an axis monitoring device that can perform measurements with high accuracy by using existing parts.

Means for Solving Problems According to the present invention, pressure detectors are provided at multiple locations on the circumference of a seal installed in a rotating machine, and pressures on the circumference are detected based on the detected pressure from the pressure detectors. A device that measures pressure distribution,
and a device for converting the shaft center position from the measured pressure distribution.

Embodiment FIGS. 1a and 1b show a state in which the shaft center is not eccentric, and FIGS. 2a and 2b show a state in which it is eccentric in the vertical direction with the device according to the present invention. In these figures, reference numeral 5 is the rotor, 15 is the seal A, B.
Or measurement holes provided at four locations on the circumference of C, 16 is a pressure impulse pipe, 17 is a pressure transducer, I8 is a measurement device that measures pressure distribution from the measured pressure from pressure transducer 17, 19 is a measurement hole Each figure shows an axis position displacement calculator that calculates the axis position from the pressure distribution. Here, the measurement hole 15, the pressure guiding pipe 16, and the pressure transducer constitute a pressure detector.

As a means of measuring the eccentricity of the axis of a rotating machine, a plurality of (four) measurement holes 15 are provided on the circumference inside the seal A, B, or C installed in this type of machine, and the measurement holes 15 are The pressure tube 16 leads to a pressure transducer 17 to determine each pressure inside the seal, and a measuring device 18 determines the pressure distribution.

This is converted into a shaft center position by a shaft center position converter 19 based on the relationship between seal eccentricity and pressure distribution that has been checked in advance.

As an example, Fig. 3 shows the pressure distribution when there is no eccentricity corresponding to Figs. 1a and 1b, and Fig. 4 shows the pressure distribution when there is a large eccentricity in the upward direction corresponding to Figs. 2a and 2b. It shows the distribution. In this way, the circumferential pressure distribution of the seal directly corresponds to the eccentricity of the shaft center, and the shaft center position can be indirectly determined from the measured pressure distribution.

Effects of the Invention According to the present invention, the degree of eccentricity of the shaft center can be determined during operation by measuring the pressure distribution inside the seal using pressure detectors installed at multiple locations on the circumference of the seal installed in the rotating machine. In the preferred embodiment, the function of the pressure sensing end can be achieved by simply machining a measurement hole in the seal, and measurement can be performed with a simple pressure transducer without the need for an expensive sensor. Sufficiently accurate measurements are possible using a center position displacement calculator.

[Brief explanation of drawings]

1a and 1b are block diagrams showing a rotating machine axis monitoring device according to the present invention together with a rotating machine without eccentricity, and FIGS. 2a and 2b are block diagrams showing a rotating machine axis monitoring device according to the present invention with an eccentric rotating machine. Configuration diagram shown with rotating machinery, Part 3
Figures 4 and 4 are diagrams illustrating pressure distributions when there is no eccentricity in the rotating machine and when there is eccentricity, and Figures 5 and 6
The figure is a sectional view showing an example of a rotating machine to which the device of the present invention is applied. 5... Rotor, 15... Measurement hole, 16... Impulse tube, 17
...Pressure transducer, 18...Measuring device, IO8, 1 city 7
& Geiyu Figure 3 Figure 4 Figure 1↑'311i Standing Figure 6

Claims (1)

[Claims] Pressure detectors installed at multiple locations on the circumference of a seal installed in a rotating machine, a device that measures the pressure distribution on the circumference based on the detected pressure from the pressure detector, and a device that measures the pressure distribution on the circumference based on the detected pressure from the pressure detector, and from the measured pressure distribution. A rotating machine axis monitoring device comprising a device for converting the axis position.