Rotary machine state observation device, rotary machine, and rotary machine state observation method

Patent metadata

Field	Value
Publication number	US-10648477-B2
Application number	US-201515533980-A
Country	US
Kind code	B2
Filing date	Oct 6, 2015
Priority date	Dec 9, 2014
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A state observation device ( 30 ) uses an ADC ( 37 ) to digitize a detection signal from a gap sensor ( 21 ) at a low-speed sampling period and uses a separation unit ( 38 ) to separate the digitized detection signal into vane detection signals considered to be for the detection of a vane of a compressor impeller and non-vane detection signals considered not to be for the detection of a vane. Further, the determination unit ( 39 ) extracts a vane peak detection signal considered to be for a vane peak by comparing a vane detection signal with vane detection signals corresponding to other vanes and non-vane detection signals, and a shaft vibration and tip clearance are determined as states of the compressor impeller on the basis of the extracted vane peak detection signal. Thus, the state observation device ( 30 ) is capable of observing the state of a rotary machine without carrying out high-speed sampling.

First claim

The invention claimed is:

1. A rotary machine state observation device, comprising:
a gap sensor to detect a distance between an impeller of a rotary machine and the gap sensor, the gap sensor being provided at an interval in a radial direction between the impeller and the gap sensor;
an analog-to-digital converter (ADC) to convert a detection signal from an analog signal into a digital signal, the detection signal being detected by the gap sensor at a predetermined sampling period; and
a digital signal processor to:
compare the detection signal converted by the ADC with a threshold value;
separate the detection signal equal to or more than the threshold value as a vane detection signal considered to be for detection of a vane of the impeller and the detection signal less than the threshold value as a non-vane detection signal considered not to be for detection of the vane;
extract a vane detection signal considered to be for a peak of the vane by a comparison of the vane detection signal with vane detection signals that correspond to other vanes and the non-vane detection signal; and
determine a state of the impeller on the basis of the extracted vane detection signal.

2. The rotary machine state observation device according to claim 1 ,
wherein the digital signal processor is to apply less weight to the vane detection signal as a deviation amount from the vane detection signal indicating the highest value increases.

3. The rotary machine state observation device according to claim 1 , wherein the predetermined sampling period is determined on the basis of a time interval at which one vane passes through a position facing the gap sensor.

4. A rotary machine, comprising:
an impeller;
a casing which accommodates the impeller; and
the state observation device according to claim 1 .

5. A rotary machine state observation method, comprising:
detecting, via a gap sensor, a distance between an impeller of a rotary machine and the gap sensor, the gap sensor being provided at an interval in a radial direction between the impeller and the gap sensor;
converting, via an analog-to-digital converter (ADC), a detection signal from an analog signal into a digital signal, the detection signal being detected by the gap sensor at a predetermined sampling period;
comparing, via a digital signal processor, the detection signal converted by the ADC with a threshold value;
separating, via a digital signal processor, the detection signal equal to or more than the threshold value as a vane detection signal considered to be for detection of a vane of the impeller and the detection signal less than the threshold value as a non-vane detection signal considered not to be for detection of the vane;
extracting, via the digital signal processor, a vane detection signal considered to be for a peak of the vane by comparing the vane detection signal with vane detection signals corresponding to other vanes and the non-vane detection signal; and
determining, via the digital signal processor, a state of the impeller on the basis of the extracted vane detection signal.

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Yoshida Tadashi
• Ogawa Shinji
• Sakamoto Koichi
• Iwasa Yukihiro

Classifications

• F02B37/00

  Engines characterised by provision of pumps driven at least for part of the time by exhaust · CPC title

• F02B33/40

  of non-positive-displacement type · CPC title

• F02C7/00

  Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants (controlling F02C9/00) · CPC title

• G01M99/00 Primary

  Subject matter not provided for in other groups of this subclass · CPC title

• G01B7/14

  for measuring distance or clearance between spaced objects or spaced apertures (G01B7/30 takes precedence) · CPC title