CN2570777Y - Orthogonal optical fibre on-line oil monitor - Google Patents

Abstract

The utility model is an online oil liquid monitor based on optical fiber technology. It is composed of optical fiber sensor and sensor detection and measurement, and the sensor is installed in series in the lubrication system pipeline of the equipment under test. Its technical feature is that the online oil monitor adopts an orthogonal optical path system, which can implement online measurement of solid particle pollutants in the oil, and reveal the wear of the detected equipment through the oil pollution degree reflected by the size of the wear particles and the particle concentration. It provides a new instrument for the implementation of equipment status detection.

Description

Orthogonal Optical Fiber Online Oil Monitor

technical field

The utility model relates to an instrument for monitoring the size and pollution degree of solid particles contained in the oil liquid by using the light scattering characteristics of abrasive particles in the oil liquid, in particular to a monitor for online monitoring of the particles in the oil liquid and the pollution degree of the oil liquid by an orthogonal optical fiber.

Background technique

At present, through the method of monitoring lubricating oil, the monitoring of equipment lubrication system is mostly carried out under laboratory conditions, mainly spectroscopic and ferrographic analysis techniques. Laboratory analysis has a time lag, the analysis process is complicated, and the analysis results are more dependent on experts. The shortcomings of experience, the instruments developed at home and abroad for on-line detection mainly measure the magnetism of wear particles, but generally the measured particles are relatively large and have low precision. At present, the online monitoring of oil detection based on optical measurement methods is developed by using the light scattering characteristics of abrasive particles in oil. For example, the HIAC/ROYCO photoelectric wear particle online monitor produced in the United States uses a fast linear scanning sensor to record light scattering. The generated pattern can detect the spatial variation signal of the particles, and the spatial variation is related to the size, optical characteristics and shape of the scattering objects, which is not suitable for online monitoring. The LaserNet Fines optical wear particle monitor developed by the U.S. Navy can be used for offline analysis and online monitoring. After the laser diode irradiates the oil, an image is generated on the optoelectronic camera. The generated image is used for wear particle identification, and all images are used for determination. Due to the characteristics reflected by the oil, this type of instrument is expensive. Domestically, there are mainly pollution detection patents (99232097) using a direct light path and a liquid concentration measurement sensor using a CCD receiver (96218109).

Contents of the invention

The purpose of the utility model is to design a kind of orthogonal optical fiber online oil liquid monitor which can detect the grain size of the particles in the oil liquid by measuring the light scattering light transmission amount of the oil liquid and reflect the condition of the equipment.

The on-line oil monitor for realizing the purpose of the utility model is composed of an optical sensing probe and a detection pipeline for oil flow, and is characterized in that the optical sensing probe is a two-way optical fiber sensing probe, and the two-way optical fiber sensing probe is connected with the oil flow The detection pipeline of liquid flow is orthogonal, the oil passes through the detection sample pool from top to bottom, and the two orthogonal incident optical paths and receiving optical path form a three-dimensional space structure with the oil flow pipeline.

The above-mentioned optical fiber sensing probe is made up of light-emitting diode, input optical fiber, collimating lens, sample cell, output optical fiber, photoelectric receiving tube, data acquisition card, signal processing computer, above-mentioned light-emitting diode, input optical fiber, collimating lens, The sample cell, output optical fiber, and photoelectric receiving tube are arranged linearly in sequence.

The detection pipeline system is composed of an oil tank with an agitator connected by pipelines, an oil suction pipe, a pressure gauge, an oil pump, an overflow valve, an adjustable throttle valve, a flow meter, a heater, a pipe for placing an optical fiber probe, and an oil sampling point, two-position three-way valve, filter and thermometer.

The on-line oil optical fiber sensor designed by the utility model can detect relatively small particle sizes by measuring the light scattering light transmission amount of the oil. The information of small-sized solid particles is reflected by the change of luminous flux to reflect the state of the equipment. The optical fiber is used as the optical channel for monitoring, which can prevent explosion and external interference, and is suitable for various industrial and mining occasions. The design of the orthogonal optical system makes the instrument have high sensitivity and stability, and the online measurement of oil can be realized without measuring the intensity of incident light.

The beneficial effect of the utility model is to study the solid particles in the oil, that is, to measure the size and distribution characteristics of all particles in the oil. Among them, the size and distribution of wear particles determine the degree of contamination of the oil, and the greater the content of abrasive particles, the more serious the degree of oil pollution.

Description of drawings

Figure 1 is the designed oil monitoring test bench.

Figure 2 is a schematic diagram of the optical fiber sensor measurement.

Figure 3 is a structural diagram of the fiber optic sensor probe.

Figure 4 is an outline view of the orthogonal fiber optic monitor.

The oil monitoring test bench in Fig. 1 consists of 1. Lubricating oil and oil tank, 2. Oil agitator, 3. Oil suction pipe, 4. Pressure gauge, 5. Oil pump, 6. Relief valve, 7. Adjustable flow valve, 8 .Flow meter, 9. Heater, 10. Installation position of fiber optic probe tube, 11. Oil sampling point, 12. Two-position three-way valve, 13. Filter, 14. Thermometer.

In Fig. 2, 15. light emitting diode, 17. collimating lens, 18. sample cell, 16.19. input and output optical fiber, 20. photoelectric receiving tube, 21. data acquisition card, 22. computer.

In Fig. 3, 23. Incident fiber connector, 24. Lens system, 25. Quartz glass, 26. Main part of optical path, 27. Sample cell, 28. Outgoing fiber connector, 29. Adjusting screw, 30. Fiber coupling connection device.

In Fig. 4, 31. connector, 32. rotary head, 33. plastic oil pipe, 34. detection pipeline, 35. 36. sensor probe, 37. photosensitive area, 38-40. channel 1, 39-41 channel 2.

Detailed ways

The on-line oil detector is embedded in position 10 of the oil test bench shown in Figure 1. The oil test bench consists of lubricating oil and oil tank 1, oil stirrer 2, oil suction pipe 3, pressure gauge 4, Oil pump 5, relief valve 6, adjustable flow valve 7, flow meter 8, heater 9, oil sampling point 11, two-position three-way valve 12, filter 13, and thermometer 14. It is mainly used to simulate the actual lubrication system of mechanical equipment to complete the online measurement research of fiber optic sensors.

The measurement principle of the sensor detection system is shown in Figure 2, which consists of a light source 15, a collimating lens 17, input and output optical fibers 16, 19, a photoelectric receiving tube 20, a data acquisition card 21, a computer 22 and other parts. The luminous flux I0 generated by the light source 15 is introduced into the measurement area, that is, the sample cell 18 arranged on the optical path, through the input optical fiber 16 and the collimating lens 17 . Part of the outgoing light that is not scattered and absorbed by the particles will be converged by the lens, and then exported to the photoelectric signal processing unit, that is, the photosensitive surface of the photoreceiving tube 20 through the second optical fiber 19 . The luminous flux I carrying the information can be measured by using the photoelectric signal amplifier, and input to the computer 22 through the data acquisition card 21 for data processing and analysis. The computer mainly completes the storage and calculation of the signal, and finally displays the measured result.

When a light source with an intensity of I0 passes through an oil (inhomogeneous medium) with a thickness of L, due to the absorption and scattering of the incident light by the particles suspended in the oil, the intensity of the transmitted light passing through the particles is weakened to I, then the light intensity The weakening follows the Beer-Lambert law, the formula is as follows:

I＝I ₀ exp(-τL)

In the formula: τ is a proportional coefficient independent of light intensity, called attenuation coefficient or turbidity; L is the measurement optical path.

τ=NKσ=π/4D ² NK where K is the extinction coefficient, which characterizes the amount of scattering of incident light by each particle, and is a function of the particle size, wavelength and the refractive index of the particle relative to the medium: N is the particle number concentration, that is Refers to the number of particles per unit volume; D is the diameter of the particle; σ is the light-receiving area of the particle. By measuring the change of light intensity, the distribution of all solid particles in the oil can be calculated inversely, so as to characterize the particle pollution degree of the equipment lubrication system.

In the embodiment shown in FIG. 3 , the sensor probe includes an incident optical fiber connector 23 , an optical path main body 26 and an outgoing optical fiber connector 28 . The centering adjustment of the optical light path is completed by adjusting the screw 29 on the optical fiber connector. Main part 26 is cylindrical shape, comprises lens system 17 and sample cell 18, and sample cell 18 is the semi-sinking tank in the middle of the cylinder, deep is 3/4 cylinder diameter, is bonded with quartz glass sheet 25,27 around the groove, isolates Oil and optics. The optical fiber connector and the main part are made of copper metal, and are connected by threads to ensure the stability of the optical system. The light emitting diode 15 and the photoelectric receiving tube 20 are connected with the incident and outgoing optical fiber connectors 23 and 28 through the optical fiber coupling device 30 .

FIG. 4 is a schematic diagram of an embodiment of a sensor using an orthogonal optical path measurement system. The two sensor probes 35 and 36 shown in FIG. The two ends of the detection pipeline 34 are sealed with a screw head 32 with a screw hole in the middle, and the oil pipe connection joint 31 is threaded with the screw head 32, and the oil is guided from the detection equipment lubrication system into the sample pool 18 of the sensor probe through the plastic oil pipe 33 . The light source irradiates from the channels 38 and 39 to the photosensitive area 37 through the optical fiber and lens system, and the oil passes through the photosensitive area from top to bottom. Two orthogonal incident light paths and a receiving light path form a three-dimensional space with the oil flow pipeline. When there are wear particles therein, scattering occurs, and the signal passes through the channels 40, 41 and is converted into an electrical signal by the photoelectric receiving tube. Since they are in the same working environment, the equations can be formed by the following two formulas. ${\left(I\right)}_1={\left(I_0\right)}_1{e}^{-\mathrm{\τL}}$ ${\left(I\right)}_2={\left(I_0\right)}_2{e}^{-\mathrm{\τL}}$

The influence of the change of the incident light intensity can be eliminated through the ratio, that is, the value of (I ₀ ) ₁ /(I ₀ ) ₂ is equal to a constant. In this way, there is no need to determine the value of the incident light intensity before each measurement, which ensures that the sensor can be used for online oil measurement. On the other hand, the two optical measurement channels can use different wavelengths for measurement, and the use of different wavelengths can effectively invert the particle distribution function.

Claims (3)

1, a kind of online oil liquid monitoring device, form by the signal piping that optical sensing probe and fluid flow, it is characterized in that the optical sensing probe is two-way optical fiber sensing probe (35), (36), two-way optical fiber sensing probe (35), (36) and mobile signal piping (34) quadrature of fluid, fluid is from top to down by the test sample pond, three-D space structure is formed with the fluid flow line in pairwise orthogonal input path (38), (39) and receiving light path (40), (41).

2, monitor as claimed in claim 1, it is characterized in that described optical fiber sensing probe is by light emitting diode (15), input optical fibre (16), collimation lens (17), sample cell (18) output optical fibre (19), photoelectric receiving tube (20), data collecting card (21), signal Processing computing machine (22) are formed the straight line setting in regular turn of above-described light emitting diode, input optical fibre, collimation lens, sample cell, output optical fibre, photoelectric receiving tube.

3, monitor as claimed in claim 1, it is characterized in that the fluid signal piping is mounted in the fuel tank (1) of the belt stirrer (2) that is linked to each other by pipeline, the fluid signal piping system that fuel sucking pipe (3), tensimeter (4), oil pump (5), surplus valve (6), adjustable throttling (7), flowmeter (8), well heater (9), the pipe of putting fibre-optical probe (10), fluid sampling spot (11), two position three-way valve (12), filtrator (13), thermometer (14) are formed.

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