On-line separation device for aviation engine lubricating oil based on microfluidics

Abstract

The present invention relates to the field of aviation technology, and in particular to an online sorting device for aircraft engine lubricating oil based on a microchannel. The present invention provides a multi-stage lubricating oil particle microchannel sorting device, in which the lubricating oil enters the sorting microchannel from the lubricating oil inlet through a micro-injection pump, and passes through the first expansion-contraction microchannel, the curved lubricating oil particle focusing microchannel, and the second expansion-contraction microchannel in sequence. The lubricating oil particles reach the large-diameter lubricating oil particle outlet or the small-diameter lubricating oil particle outlet according to their diameters to achieve particle sorting. The present invention provides another spiral magnetophoretic lubricating oil particle microchannel sorting device, which achieves particle sorting by arranging an electromagnetic coil on the outside of the lubricating oil particle sorting microchannel so that particles with different magnetic susceptibility undergo offset movement. The sorting device provided by the present invention can achieve high-precision online sampling of lubricating oil high-pressure pipelines, and has the characteristics of small size and high stability.

Description

Technical Field

[0001] The invention relates to the field of aviation technology, and in particular to an aviation engine lubricating oil online sorting device based on a microchannel. Background Art

[0002] The internal structure of aircraft engines is complex, and parts wear is very likely to occur under high temperature and high load conditions, which seriously threatens the operational safety of aircraft engines. Therefore, multi-parameter online real-time detection and fault diagnosis of aircraft engine wear status is of great significance to accelerate the development of high-performance aircraft engines in my country, ensure flight safety, and avoid catastrophic safety accidents.

[0003] Lubricating oil is the "blood" of aircraft engines. It not only lubricates, cools and cleans the engine's bearings, gears and other moving parts, but is also an important window for reflecting wear-related faults inside the engine. When the internal parts of an aircraft engine are worn, the metal abrasive particles in the corresponding parts will enter the lubricating oil system and circulate with the lubricating oil. The characteristic parameters such as the size, shape and material content of the metal abrasive particles are closely related to the wear part, wear mechanism and wear degree. Lubricating oil testing has become an important means to judge the health status of the engine and predict faults during the development and test of aircraft engines.

[0004] In order to accurately reflect the distribution of lubricating oil pollutant concentration during the operation of aircraft engines, which is of great significance to ensure the stable operation of aircraft engines, the detection accuracy of aircraft engine lubricating oil pollutant concentration can be improved by sorting and counting mechanical wear particles in the lubricating oil.

[0005] The current aviation engine lubricating oil sorting technology mainly includes: (1) Iron spectrum analysis technology: using electromagnetic technology to set up a high-intensity gradient magnetic field, using magnetic force to separate the abrasive particles in the lubricating oil in order according to size, and through microscopic observation of the morphology and size of the separated sediments on the substrate, the particle size characteristics in the lubricating oil are analyzed to determine the wear condition of the aircraft engine parts. Since this technology requires the use of a microscope to observe the particle size distribution, the lubricating oil sampling requirements are relatively strict, and the observer's measurement experience also affects the monitoring results, so its detection effect is not good. (2) Sieve hole sorting: The wear metal particles in the lubricating oil are sorted through sieve holes of different sizes, but this sorting method has a small flux when sorting lubricating oil, and cannot achieve high-throughput sorting in a short time. In addition, large particles blocking the sieve holes can easily reduce the sorting efficiency. (3) Dielectrophoresis separation: Lubricating oil particles are subjected to induced polarization migration in a uniform strong electric field. Different metal particles in the lubricating oil receive different forces, which enables precise control and separation of particles in the lubricating oil. However, this technology has a small sorting flux and low sorting efficiency. It also requires high-intensity electric field control and has high requirements for the sorting environment. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and to propose an on-line sorting device for aircraft engine lubricating oil based on microfluidics, which can achieve on-line high-throughput and high-efficiency sorting of aircraft engine lubricating oil.

[0007] To achieve the above object, the present invention adopts the following specific technical solutions:

[0008] The multi-stage lubricating oil particle microfluidic channel sorting device provided by the present invention comprises at least one substrate, each of which is provided with a lubricating oil inlet, a large-diameter lubricating oil particle outlet, a small-diameter lubricating oil particle outlet and at least one sorting channel, each of which is provided with a first expansion-contraction microfluidic channel, a curved lubricating oil particle focusing microfluidic channel and a second expansion-contraction microfluidic channel in sequence, the two ends of the first expansion-contraction microfluidic channel are respectively connected to the lubricating oil inlet and the curved lubricating oil particle focusing microfluidic channel, one end of the second expansion-contraction microfluidic channel is connected to the curved lubricating oil particle focusing microfluidic channel, and the other end of the second expansion-contraction microfluidic channel is respectively connected to the large-diameter lubricating oil particle outlet and the small-diameter lubricating oil particle outlet.

[0009] Preferably, the multi-stage lubricating oil particle microfluidic sorting device is a multi-layer structure, comprising two or more substrates, the lubricating oil inlet, large-diameter lubricating oil particle outlet, and small-diameter lubricating oil particle outlet on each substrate are interconnected, and the sorting channels of each substrate are not interconnected.

[0010] Preferably, the material of the substrate is polydimethylsiloxane, and each substrate is separated by a glass sheet.

[0011] The spiral magnetophoretic lubricating oil particle microfluidic channel sorting device provided by the present invention comprises a lubricating oil inlet, a spiral microfluidic channel and a lubricating oil particle sorting microfluidic channel connected in sequence, the other end of the lubricating oil particle sorting microfluidic channel is respectively connected to the large-diameter lubricating oil particle outlet and the small-diameter lubricating oil particle outlet, and an electromagnetic coil is arranged on the outside of the lubricating oil particle sorting microfluidic channel for causing particles with different magnetic susceptibility to undergo an offset movement in a certain direction.

[0012] Preferably, the cross-sectional dimensions of the flow channel at both ends of the lubricating oil particle sorting micro-channel are smaller than the cross-sectional dimensions of the flow channel in the middle portion.

[0013] The present invention can achieve the following technical effects:

[0014] The microchannel-based on-line aircraft engine lubricating oil sorting device provided by the present invention can realize high-precision online sampling of lubricating oil high-pressure pipelines; it adopts a multi-layer and multi-stage composite lubricating oil sorting microchannel device and a spiral magnetophoresis lubricating oil sorting microchannel to realize high-throughput sorting of aircraft engine lubricating oil particles, and has the characteristics of small size and high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of a multi-stage single-layer lubricating oil particle microchannel sorting device provided according to the first embodiment of the present invention.

[0016] Figure 2 It is a schematic structural diagram of a multi-stage and multi-layer lubricating oil particle microchannel sorting device provided according to the second embodiment of the present invention.

[0017] Figure 3 It is a structural schematic diagram of the sorting channels and the lubricating oil inlet or lubricating oil particle outlet of the multi-stage and multi-layer lubricating oil particle microchannel sorting device provided according to the second embodiment of the present invention.

[0018] Figure 4 Schematic diagram of the structure of the spiral magnetophoretic lubricating oil particle microchannel sorting device provided according to the third embodiment of the present invention.

[0019] Reference numerals include:

[0020] Lubricating oil inlet 1, first expansion-contraction microfluidic channel 2, curved lubricating oil particle focusing microfluidic channel 3, second expansion-contraction microfluidic channel 4, large diameter lubricating oil particle outlet 5, small diameter lubricating oil particle outlet 6, polydimethylsiloxane 7, glass sheet 8, sorting channel 9, lubricating oil inlet / lubricating oil particle outlet 10, spiral microfluidic channel 11, electromagnetic coil 12, lubricating oil particle sorting microfluidic channel 13. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0023] Embodiment 1

[0024] Figure 1 The structure of the multi-stage single-layer lubricating oil particle microchannel sorting device provided in the first embodiment of the present invention is shown.

[0025] like Figure 1As shown, the substrate of the multi-stage lubricating oil particle microfluidic sorting device is provided with a lubricating oil inlet 1, a large-diameter lubricating oil particle outlet 5, a small-diameter lubricating oil particle outlet 6 and a plurality of sorting channels, each sorting channel is provided with a first expansion-contraction microfluidic channel 2, a curved lubricating oil particle focusing microfluidic channel 3 and a second expansion-contraction microfluidic channel 4 in sequence, the first expansion-contraction microfluidic channel 2 is connected with the lubricating oil inlet 1 and the curved lubricating oil particle focusing microfluidic channel 3, one end of the second expansion-contraction microfluidic channel 4 is connected with the curved lubricating oil particle focusing microfluidic channel 3, and the other end is connected with the large-diameter lubricating oil particle outlet 5 and the small-diameter lubricating oil particle outlet 6. The large-diameter lubricating oil particle outlet 5 is provided above the small-diameter lubricating oil particle outlet 6, and the shape of the curved lubricating oil particle focusing microfluidic channel 3 can be a periodically distributed sine or cosine type.

[0026] The lubricating oil enters the sorting microchannel from the lubricating oil inlet 1 through a microinjection pump, and passes through the first expansion-contraction microchannel 2, the curved lubricating oil particle focusing microchannel 3 and the second expansion-contraction microchannel 4 in sequence. The lubricating oil particles reach the large-diameter lubricating oil particle outlet 5 or the small-diameter lubricating oil particle outlet 6 according to their diameter.

[0027] The cross-sectional dimensions of the first expansion-contraction microchannel 2 and the second expansion-contraction microchannel 4 along the flow direction of the lubricating oil first increase and then decrease. The part with a larger cross-sectional dimension of the channel is the expansion area, and the area with a smaller channel dimension is the contraction area. The sorting channel adopts a contraction-expansion-bend-expansion design, which mainly utilizes the inertial force and drag force of the lubricating oil particles flowing through the above-mentioned channel due to the different particle sizes to focus on different positions of the channel to achieve the purpose of sorting the lubricating oil particles. When the lubricating oil particles enter the contraction area from the expansion area, the particles will be focused at the equilibrium position under the joint action of the inertial force and the drag force, in which the inertial lift is affected by the flow velocity of the fluid, the particle diameter and the cross-sectional dimension of the channel. Since the influence of the particle diameter on the inertial lift is much greater than the drag force, the relatively larger particles migrate to the top of the channel wall faster than the smaller particles, and finally the sorting of the lubricating oil particles is achieved.

[0028] Embodiment 2

[0029] Figure 2 The structure of the multi-stage and multi-layer lubricating oil particle microchannel sorting device provided in the second embodiment of the present invention is shown. Figure 3 The structure of the sorting channel and the lubricating oil inlet or lubricating oil particle outlet of the multi-stage and multi-layer lubricating oil particle microchannel sorting device provided in the second embodiment of the present invention is shown.

[0030] like Figure 2 and Figure 3As shown, the multi-stage lubricating oil particle microfluidic sorting device is a multi-layer structure, including multiple substrates, each of which is provided with a lubricating oil inlet 1, a large-diameter lubricating oil particle outlet 5, a small-diameter lubricating oil particle outlet 6 and at least one sorting channel, the lubricating oil inlet / lubricating oil particle outlet 10 on each substrate is interconnected, and the sorting channels 9 of each substrate are not interconnected.

[0031] Each substrate is separated by a glass sheet 8 , and the interior of each substrate outside the lubricating oil inlet, the large-diameter lubricating oil particle outlet, the small-diameter lubricating oil particle outlet and the sorting channel 9 is filled with polydimethylsiloxane 7 .

[0032] The multi-stage and multi-layer microfluidic channel sorting device for lubricating oil particles adopts a passive sorting method based on microfluidic inertial focusing. It utilizes the unique structure of the microchannel when the lubricating oil flows in the microchannel to focus particles of different sizes in the lubricating oil at different positions in the microchannel. The size sorting of lubricating oil particles is achieved by exporting the lubricating oil particles at different focusing positions. On the basis of ensuring the sorting capture rate of lubricating oil particles, high-throughput and rapid sorting of lubricating oil particles is achieved.

[0033] Embodiment 3

[0034] Figure 4 The structure of the spiral magnetophoretic lubricating oil particle microchannel sorting device provided in the third embodiment of the present invention is shown.

[0035] like Figure 4 As shown, the spiral magnetophoretic lubricating oil particle microfluidic channel sorting device includes a lubricating oil inlet 1, a spiral microfluidic channel 11 and a lubricating oil particle sorting microfluidic channel 13 connected in sequence, the outlet end of the lubricating oil particle sorting microfluidic channel 13 is connected to a large-diameter lubricating oil particle outlet 5 and a small-diameter lubricating oil particle outlet 6, and an electromagnetic coil 12 is arranged on the outside of the lubricating oil particle sorting microfluidic channel 13.

[0036] The lubricating oil is pumped from the lubricating oil inlet into the spiral magnetophoretic lubricating oil particle microfluidic sorting device through the sample injection pump to sort the solid particles of lubricating oil size. When the lubricating oil flows in the pipeline, the particles in the lubricating oil are simultaneously affected by the inertial force and the drag force, and are migrated to a specific equilibrium position in the pipeline. The distribution of the equilibrium position depends on the shape of the flow channel cross section. According to the effect of the inertial force, particles of different sizes can be migrated to different equilibrium positions in the lubricating oil microfluid to achieve the sorting of lubricating oil particles.

[0037] The spiral magnetophoretic lubricating oil particle microchannel sorting device adopts a spiral flow channel with a continuous and uniform curvature. When the lubricating oil particles pass through the flow channel, the large particles have a greater inertial force and their equilibrium position is closer to the inner wall of the spiral, while the small particles are more susceptible to the drag force and their equilibrium position in the flow channel is far away from the inner wall, thus achieving the purpose of separating large and small particles. By controlling the cross-sectional size, length and curvature radius of the lubricating oil flow channel, the particles can flow out through various outlets to achieve preliminary particle sorting.

[0038] The lubricating oil particles are focused on different positions in the spiral flow channel by controlling the flow rate of the lubricating oil particles in the spiral flow channel, so that the lubricating oil particles can be initially sorted. The flow channel is expanded at the outlet of the lubricating oil particle sorting microchannel 13, and an electromagnetic coil 12 is set. The magnetophoresis sorting technology relies on the magnetic field to generate a certain magnetic field gradient in the separation area, which causes the particles with different magnetic susceptibility to offset in a certain direction. Particles with different performance parameters can be separated to different positions. Under the action of the high-intensity gradient magnetic field, the deposition distance of large abrasive particles is closer to the electromagnetic coil, that is, channel 5, and the deposition distance of small abrasive particles is farther from the coil, that is, outlet 6.

[0039] The spiral magnetophoretic lubricating oil particle microchannel sorting device combines inertial passive sorting with magnetophoretic active sorting. The lubricating oil particles flow through the inertial spiral microchannel and the magnetophoretic microchannel in the microchannel in turn. The passive sorting technology of lubricating oil particles is used to achieve high-throughput sorting of lubricating oil, and magnetophoretic sorting is used to achieve efficient capture and sorting of lubricating oil particles.

[0040] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0041] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

[0042] The above specific implementations of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A multi-stage lubricating oil particle microchannel sorting device, characterized in that: It comprises at least one substrate, each of which is provided with an oil inlet, a large-diameter oil particle outlet, a small-diameter oil particle outlet and at least one sorting channel, each of which is provided with a first expansion-contraction microfluidic channel, a curved oil particle focusing microfluidic channel and a second expansion-contraction microfluidic channel in sequence, the two ends of the first expansion-contraction microfluidic channel are respectively connected to the oil inlet and the curved oil particle focusing microfluidic channel, one end of the second expansion-contraction microfluidic channel is connected to the curved oil particle focusing microfluidic channel, the other end of the second expansion-contraction microfluidic channel is respectively connected to the large-diameter oil particle outlet and the small-diameter oil particle outlet, and the large-diameter oil particle outlet is arranged above the small-diameter oil particle outlet.

2. The multi-stage lubricating oil particle microchannel sorting device according to claim 1 is characterized in that: The multi-stage lubricating oil particle microfluidic sorting device is a multi-layer structure, comprising two or more substrates. The lubricating oil inlet, large-diameter lubricating oil particle outlet, and small-diameter lubricating oil particle outlet on each substrate are interconnected, and the sorting channels of each substrate are not interconnected.

3. The multi-stage lubricating oil particle microchannel sorting device according to claim 2 is characterized in that: The material of the substrate is polydimethylsiloxane, and each substrate is separated by a glass sheet.

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