Coaxial capacitive sensor and a method for on-line monitoring and diagnosing engine lubricating oil abrasive particles

Patent metadata

Field	Value
Publication number	US-11061010-B2
Application number	US-202017049973-A
Country	US
Kind code	B2
Filing date	Mar 17, 2020
Priority date	Apr 9, 2019
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A coaxial capacitive sensor includes a sensor lubricating oil inlet and a sensor lubricating oil outlet. The sensor lubricating oil inlet and the sensor lubricating oil outlet separately communicate with the interior of the coaxial capacitive sensor. The interior of the coaxial capacitive sensor is provided with a center bearing, electrode support insulating substrates, and electrode plates. The plurality of electrode support insulating substrates and the center bearing divide the interior of the coaxial capacitive sensor into a plurality of detection sub-spaces, and the electrode plates are attached onto the electrode support insulating substrates, respectively. The coaxial capacitive sensor provided by the present invention can be arranged in a lubricating oil pipeline to avoid the influences of environmental factors on the testing results, and can on-line detect the characteristics of the lubricating oil abrasive particles efficiently.

First claim

What is claimed is:

1. A coaxial capacitive sensor, comprising:
a sensor lubricating oil inlet and a sensor lubricating oil outlet;
wherein
the sensor lubricating oil inlet and the sensor lubricating oil outlet separately communicate with an interior of the coaxial capacitive sensor;
wherein the interior of the coaxial capacitive sensor is provided with a center bearing, a plurality of electrode support insulating substrates and a plurality of electrode plates;
the plurality of electrode support insulating substrates and the center bearing divide the interior of the coaxial capacitive sensor into a plurality of detection sub-spaces;
the plurality of electrode plates are attached onto the plurality of electrode support insulating substrates, respectively; and
the plurality of electrode plates comprise a plurality of planar electrodes and a plurality of curved electrodes to form a plurality of planar non-parallel capacitors and a plurality of curved parallel capacitors in the plurality of detection sub-spaces.

2. The coaxial capacitive sensor of claim 1 , wherein
the coaxial capacitive sensor has a circular truncated cone configuration.

3. The coaxial capacitive sensor of claim 1 , wherein the coaxial capacitive sensor has a cylindrical configuration.

4. A method for online monitoring and diagnosing engine lubricating oil abrasive particles using the coaxial capacitive sensor of claim 1 , comprising:
step a: allowing lubricating oil carrying the engine lubricating oil abrasive particles to enter the plurality of detection sub-spaces, and synchronously collecting monitoring signals of a plurality of capacitive sensors within the plurality of detection sub-spaces; and
step b: extracting signal characteristics of two pairs of non-parallel capacitors from a time frequency domain to detect and diagnose morphological characteristics and quantitative characteristics of the engine lubricating oil abrasive particles.

5. The method of claim 4 , wherein
in step b, the plurality of detection sub-spaces detect and diagnose the morphological characteristics of the engine lubricating oil abrasive particles by using a correspondence relationship between the engine lubricating oil abrasive particles of different morphologies and changes of the signal characteristics.

6. The method of claim 4 , wherein
in step b, the plurality of detection sub-spaces perform quantitative monitoring and diagnosing on a number of the engine lubricating oil abrasive particles by identifying signal pulse changes generated when the engine lubricating oil abrasive particles pass.

7. The method of claim 4 , wherein
influences of environment factors comprising a temperature and a flow rate on a diagnosis result are eliminated through a differential comparison and compensation of capacitive sensing signals in the plurality of detection sub-spaces of the coaxial capacitive sensor.

8. The method of claim 4 , further comprising a method for diagnosing and detecting a change of a mass of the engine lubricating oil abrasive particle, wherein the method for diagnosing and detecting the change of the mass of the engine lubricating oil abrasive particle comprises the following steps:
detecting a change ΔC of a capacitance in combination with the coaxial capacitive sensor, and measuring a change Δv of a medium flow rate and a change Δt of a medium temperature;
marking relationships between the capacitance and the medium flow rate, the medium temperature and the mass of the engine lubricating oil abrasive particle as: C v =f(v), C t =g(t), and C m =h(m), respectively;
changes of the capacitance caused by the medium flow rate, the medium temperature and the mass of the engine lubricating oil abrasive particle being: ΔC v =f(v+Δv), ΔC t =g(t+Δt)−g(t), and C m =h(m+Δm)−h(m), respectively; and
obtaining ΔC m =ΔC−ΔC v −ΔC t to obtain the change of the mass of the engine lubricating oil abrasive particle.

9. The method of claim 4 , wherein
the coaxial capacitive sensor has a circular truncated cone configuration.

10. The method of claim 9 , wherein
in step b, the plurality of detection sub-spaces detect and diagnose the morphological characteristics of the engine lubricating oil abrasive particles by using a correspondence relationship between the engine lubricating oil abrasive particles of different morphologies and changes of the signal characteristics.

11. The n od of claim 9 , wherein
in step b, the plurality of detection sub-spaces perform quantitative monitoring and diagnosing on a number of the engine lubricating oil abrasive particles by identifying signal pulse changes generated when the engine lubricating oil abrasive particles pass.

12. The method of claim 9 , wherein
influences of environment factors comprising a temperature and a flow rate on a diagnosis result are eliminated through a differential comparison and compensation of capacitive sensing signals in the plurality of detection sub-spaces of the coaxial capacitive sensor.

13. The method of claim 9 , further comprising a method for diagnosing and detecting a change of a mass of the engine lubricating oil abrasive particle, wherein the method for diagnosing and detecting the change of the mass of the engine lubricating oil abrasive particle comprises the following steps:
detecting a change ΔC of a capacitance in combination with the coaxial capacitive sensor, and measuring a change Δv of a medium flow rate and a change Δt of a medium temperature;
marking relationships between the capacitance and the medium flow rate, the medium temperature and the mass of the engine lubricating oil abrasive particle as: C v =f(v), C t =g(t), and C m =h(m), respectively;
changes of the capacitance caused by the medium flow rate, the medium temperature and the mass of the engine lubricating oil abrasive particle being: ΔC v =f(v=Δv), ΔC t =g(t+Δt)−g(t), and ΔC m =h(m+Δm)−h(m), respectively; and
obtaining ΔC m =ΔC−ΔC v −ΔC t to obtain the change of the mass of the engine lubricating oil abrasive particle.

14. The method of claim 4 , wherein
the coaxial capacitive sensor has a cylindrical configuration.

15. The method of claim 14 , wherein
in step b, the plurality of detection sub-spaces detect and diagnose the morphological characteristics of the engine lubricating oil abrasive particles by using a correspondence relationship between the engine lubricating oil abrasive particles of different morphologies and changes of the signal characteristics.

16. The method of claim 14 , wherein in step b, the plurality of detection sub-spaces perform quantitative monitoring and diagnosing on a number of the engine lubricating oil abrasive particles by identifying signal pulse changes generated when the engine lubricating oil abrasive particles pass.

17. The method of claim 14 , wherein
influences of environment factors comprising a temperature and a flow rate on a diagnosis result are eliminated through a differential comparison and compensation of capacitive sensing signals in the plurality of detection sub-spaces of the coaxial capacitive sensor.

18. The method of claim 14 , further comprising a method for diagnosing and detecting a change of a mass of the engine lubricating oil abrasive particle, wherein the method for diagnosing and detecting the change of the mass of the engine lubricating oil abrasive particle comprises the following steps:
detecting a change ΔC of a capacitance in combination with the coaxial capacitive sensor, and measuring a change Δv of a medium flow rate and a change Δt of a medium temperature;
marking rel

Assignees

• Univ Xiamen

Inventors

• Wang Yishou
• You Yancheng
• Wu Diheng
• Lin Tingwei
• Qing Xinlin
• Sun Hu

Classifications

• G01N27/226

  Construction of measuring vessels; Electrodes therefor · CPC title

• G01N33/2858

  Metal particles · CPC title

• G01N15/0266

  with electrical classification · CPC title

• G01N15/1031

  by measuring electrical or magnetic effects · CPC title

• G01N33/2888 Primary

  Lubricating oil characteristics, e.g. deterioration (lubricating properties G01N33/30) · CPC title