CN105823711A - Online monitoring method for oil abrasive particles - Google Patents

Abstract

The invention discloses an online monitoring method for oil abrasive particles. According to the suggestion of the present invention, the following steps are included: detecting the abrasive particle signal in the oil pipeline connected to the lubricating oil circuit of the gearbox by an air-oil abrasive particle sensor; The abrasive particle signal is transmitted to the pre-amplification and noise reduction unit; the pre-amplification and noise reduction unit amplifies and reduces the noise of the detected abrasive particle signal; and transmits the amplified and noise-reduced abrasive particle signal to the particle A signal detection unit; the particle signal detection unit generates a particle signal; the particle signal detection unit transmits the particle signal to a false signal screening unit; the false signal screening unit screens the particle signal; The particle signal is subjected to eigenvalue extraction and a frequency spectrum is generated.

Description

On-line Monitoring Method of Oil Wear Particles

technical field

The invention relates to the technical field of on-line detection, in particular to an on-line monitoring method for oil abrasive particles.

Background technique

At present, oil wear detection is used in the oil detection system of wind turbines. According to the master's thesis of Beijing Jiaotong University, two types of detection principles are proposed: one of which is to indirectly judge the interior of the gearbox by detecting the physical characteristics of ferromagnetic abrasive particles in the oil. The wear of parts, this method has higher accuracy and reliability than vibration detection; the other is to judge the quality of the gearbox by detecting the quality of the oil, such as oil viscosity, water content, pollution degree, etc. The relatively successful wear particle detection sensors in foreign countries mainly include FerroSCAN sensor and MetalSCAN sensor developed by GASTOPS company in Canada, multi-channel wear particle counter and laser scanning sensor developed by HIAC/ROYCO company in the United States (not continuous online monitoring) and PROFTECHNIK company in Germany Developed by WearScanner[i6]. The MetalSCAN wear particle sensor can distinguish the particle types according to the signal phase of the non-ferromagnetic particles and the opposite characteristic of the ferromagnetic particle information, and determine the size of the wear particles according to the amplitude of the signal.

Gearboxes, main bearings, blade bearings, generator bearings, yaw system bearings, and brake systems in wind turbines all need lubrication to ensure normal operation. Important information on lubrication, friction, and wear status is reflected in various indicators of the oil. At present, related technologies for on-line analysis of oil products have emerged, such as oil cleanliness. The purpose of such techniques is to help determine when to change the oil, but it is not effective in predicting component damage, especially early wear.

For gearbox faults caused by gear wear, oil wear particle detection shows a more sensitive detection performance than vibration monitoring. But there are still deficiencies: the number of gears inside the gearbox is large, and the faulty parts cannot be accurately located through the detection of metal abrasive particles. Moreover, due to the interference of false signals, oil wear particle detection cannot make accurate diagnosis of gearbox faults like vibration state detection. The inductive-based wear particle online sensor developed by the Reliability Engineering Research Institute of Wuhan University of Technology can only roughly distinguish the size and material of wear particles. In addition, there are ferromagnetic wear particle on-line monitor developed by Shijiazhuang Railway Institute and ultrasonic wear particle monitoring sensor developed by Naval Engineering University.

However, these papers and patents do not take into account the accurate distinction between true and false signals, so that the ferromagnetic information in the oil cannot be accurately extracted.

Contents of the invention

In order to solve at least one of the problems mentioned in the background art, the present invention provides an online monitoring method for oil abrasive particles that ensures the authenticity and accuracy of signals.

In order to achieve the above object, the present invention provides an online monitoring method for oil abrasive particles, comprising the following steps:

The air-oil-liquid abrasive particle sensor detects the abrasive particle signal in the oil pipeline connected to the lubricating oil circuit of the gearbox;

Transmitting the detected wear particle signal to the preamplifier noise reduction unit;

The pre-amplification and noise reduction unit amplifies and reduces the noise of the detected wear particle signal;

Transmitting the amplified and noise-reduced wear particle signal to the particle signal detection unit;

The particle signal detection unit generates a particle signal;

The particle signal detection unit transmits the particle signal to a false signal screening unit;

The false signal screening unit screens the particle signal;

Perform feature value extraction on the screened particle signal to generate a frequency spectrum.

Optionally, the false signal discriminating unit utilizes a discriminating algorithm between false particle signals and real signals caused by environmental interference to discriminate.

Optionally, the air-oil-liquid abrasive particle sensor will be used to detect the abrasive particle signal in the oil pipeline connected to the lubricating oil circuit of the gearbox during the working process of the gearbox.

Optionally, select the appropriate data sampling frequency according to the effective sampling frequency of the selected oil abrasive particle sensor, then select the data acquisition card, and embed it into the main controller with the corresponding interface circuit, and connect the main controller to the computer , so as to realize the acquisition and digital-to-analog conversion of analog signals.

Beneficial effects of the online monitoring method for oil abrasive particles of the present invention: the online monitoring method for oil abrasive particles of the present invention can accurately monitor the ferromagnetic content in lubricating oil, and the false signal discrimination algorithm can discriminate the disturbing ferromagnetic signals in real time to ensure the integrity of the signals True and accurate.

Description of drawings

Fig. 1 is a schematic flow chart of the online monitoring method for oil abrasive particles of the present invention.

Fig. 2 is a structural schematic diagram of the online monitoring method for oil abrasive particles of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, various embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that, in each implementation manner of the present invention, many technical details are provided for readers to better understand the present application. However, even without these technical details and various changes and modifications based on the following implementation modes, the technical solution claimed in each claim of the present application can be realized.

In order to solve the above-mentioned technical problems, the present invention provides an online monitoring method for oil abrasive particles. This embodiment is described in detail with reference to FIGS. 1 to 2 . Fig. 1 is a schematic flow chart of the on-line monitoring method for oil abrasive particles of the present invention, and Fig. 2 is a schematic structural diagram of the on-line monitoring method for oil abrasive particles of the present invention.

A method for on-line monitoring of oil abrasive particles provided by the present invention, as shown in Figure 1, comprises the following steps: Step 10: the wind oil liquid abrasive particle sensor detects the abrasive particle signal in the oil liquid pipeline connected to the lubricating oil circuit of the gearbox; step 11: Transfer the detected abrasive particle signal to the preamplifier noise reduction unit; Step 12: The preamplifier noise reduction unit amplifies and reduces noise on the detected abrasive particle signal; Step 13: The amplified and noise-reduced wear particle signal is transmitted to the particle signal detection unit; step 14: the particle signal detection unit generates a particle signal; step 15: the particle signal detection unit transmits the particle signal to a false signal discrimination unit; Step 16: The false signal screening unit screens the particle signal; Step 17: Performs feature value extraction on the screened particle signal and generates a spectrum. In step 16, the false signal screening unit uses the screening algorithm of the false particle signal caused by environmental interference and the real signal to screen, and in step 10, the wind, oil and liquid abrasive particle sensor will be used to detect gears during the working process of the gearbox. The wear particle signal in the oil pipeline connected to the lubricating oil circuit of the oil tank, or the following method can be further selected: select the appropriate data sampling frequency according to the effective sampling frequency of the selected oil wear sensor, and then select the data acquisition card, and use it in the matching corresponding The interface circuit is embedded in the general controller, and connects the general controller with the computer, so as to realize the acquisition of the analog signal and the digital-to-analog conversion.

Wind turbines use DN50, DN32 and other oil pipes with larger apertures, and the corresponding through-hole diameters are 40mm and 27mm, which are far larger than the particle size (200-1500μm) to be inspected. Therefore, the high gain amplification and noise suppression of the weak signal of the oil wear particle sensor are very important. After calculation, the gain multiple should reach at least 90dB, and it is also necessary to suppress the harsh environmental noise on site.

When judging the condition of oil abrasive particles, combined with the false signal screening algorithm, the condition of oil abrasive particles can be determined, and the wear condition of the fan gearbox can be obtained, so as to realize the online detection of the gearbox.

The present invention has following advantage at least:

1. Oil abrasive particle is a non-destructive testing method, which is suitable for wind power testing and can reduce wind power maintenance costs, prolong service life and ensure safe power supply;

2. The test is almost not limited by the material and component geometry, and has strong applicability;

3. This method can communicate with the pitch system and brake system of the wind power generating set, and control the wind turbine and stop the protection equipment when the gearbox is extremely worn.

Those of ordinary skill in the art can understand that the above-mentioned embodiments are specific examples for realizing the present invention, and in practical applications, various changes can be made to it in form and details without departing from the spirit and spirit of the present invention. scope.

Claims (4)

1. an oil liquid abrasive grain on-line monitoring method, it is characterised in that comprise the following steps:

Grain signal in wind oil liquid abrasive grain sensor detection gear box lubricating oil loop-coupled fluid pipeline；

The described grain signal detected is passed to preposition amplifying and noise reducing unit；

The described grain signal detected is amplified and noise reduction by described preposition amplifying and noise reducing unit；

Grain signal after amplification and noise reduction is passed to particle signal detector unit；

Described particle signal detector unit produces particle signal；

Described particle signal is passed to glitch discriminator unit by described particle signal detector unit；

Described particle signal is screened by described glitch discriminator unit；

Described particle signal after screening is carried out characteristics extraction and produces frequency spectrum.

Oil liquid abrasive grain on-line monitoring method the most according to claim 1, it is characterised in that: described glitch discriminator unit utilizes the examination algorithm of false particle signal that environmental disturbances causes and actual signal to screen.

Oil liquid abrasive grain on-line monitoring method the most according to claim 1, it is characterised in that: described wind oil liquid abrasive grain sensor will be used for gear-box and detect grain signal in gear box lubricating oil loop-coupled fluid pipeline in the course of the work.

Oil liquid abrasive grain on-line monitoring method the most according to claim 3, it is characterized in that: according to the suitable data sampling frequency of efficiently sampling frequency selection purposes of selected oil liquid abrasive grain sensor, then data collecting card is chosen, at supporting corresponding interface circuit, it is embedded in master controller, master controller is connected with computer, thus realizes collection and the digital-to-analogue conversion of analogue signal.