CN-121995040-A - Fluid lubrication pressure and temperature monitoring method and quantum dot sensor

CN121995040ACN 121995040 ACN121995040 ACN 121995040ACN-121995040-A

Abstract

The invention discloses a fluid lubrication pressure and temperature monitoring method and a quantum dot sensor, and belongs to the technical field of fluid lubrication state monitoring. The method comprises the steps of uniformly dispersing perovskite quantum dots in basic lubricating oil, preparing quantum dot lubricating oil, introducing the quantum dot lubricating oil into a lubricating system to be monitored, exciting the quantum dots in the lubricating oil in the running process of the lubricating system, collecting fluorescence spectrum signals of the quantum dots in real time, extracting fluorescence peak wavelength and fluorescence intensity, converting collected fluorescence information into pressure information and temperature information according to a pre-established pressure-peak position calibration relation and a temperature-intensity calibration relation, and distinguishing the fluorescence signals of a contact area and a non-contact area through a time dimension or a space dimension, so as to realize in-situ distinguishing and monitoring of the pressure and the temperature in the lubricating system. The invention realizes the double-parameter in-situ differential measurement of pressure and temperature in the same lubricating fluid, and avoids the interference of the traditional contact measurement on the lubricating flow field.

Inventors

ZHANG PAN
ZOU SHENG
YAN KE
SUN JIANNAN
CHEN FEI
MA SHUAIJUN
HONG JUN

Assignees

西安交通大学

Dates

Publication Date: 20260508
Application Date: 20260326

Claims (8)

1. A method of monitoring the pressure and temperature of a fluid lubrication comprising the steps of: Uniformly dispersing perovskite quantum dots in basic lubricating oil, preparing quantum dot lubricating oil, and introducing the quantum dot lubricating oil into a lubricating system to be monitored; In the running process of the lubricating system, exciting quantum dots in lubricating oil and collecting fluorescence spectrum signals of the quantum dots in real time; The method comprises the steps of collecting fluorescence spectrum signals, extracting two characteristic parameters of fluorescence peak wavelength and fluorescence intensity from the collected fluorescence spectrum signals, converting the fluorescence peak wavelength collected by a contact area into pressure information of a lubrication contact area according to a pre-established pressure-peak position calibration relation, converting the fluorescence intensity collected by a non-contact area into temperature information of a lubrication oil film according to a pre-established temperature-intensity calibration relation, and distinguishing the fluorescence signals of the contact area and the non-contact area through a time dimension or a space dimension so as to realize in-situ distinguishing and monitoring of the pressure and the temperature in the lubrication system.
2. The method of monitoring the pressure and temperature of a fluid lubrication according to claim 1, wherein the contact area is an area where bearing contact is periodically formed between a moving part and a mating surface in the lubrication system; In the monitoring process, the collection time of the fluorescent signals is synchronized with the movement period of the lubrication system, when the collection time corresponds to the time window of the contact area of the moving part, the collected fluorescent signals are judged to be from the contact area, the fluorescence peak wavelength of the fluorescent signals is extracted to be used for acquiring pressure information, when the collection time corresponds to the time window of the contact area of the moving part, the collected fluorescent signals are judged to be from the non-contact area, the fluorescence intensity of the fluorescent signals is extracted to be used for acquiring temperature information, and the time-sharing monitoring of the pressure and the temperature is realized by adjusting the collection frequency of the signals and combining the movement period parameters of the lubrication system.
3. The method for monitoring the lubrication pressure and the temperature of the fluid according to claim 1, wherein the pressure-peak position calibration relation is established by applying different known pressures to the quantum dot lubricating oil under the condition of constant temperature, measuring the fluorescence peak wavelength corresponding to each pressure point, and fitting to obtain the linear relation between the pressure and the fluorescence peak wavelength.
4. The method for monitoring the lubrication pressure and the temperature of the fluid according to claim 1, wherein the temperature-intensity calibration relation is established by placing the quantum dot lubricating oil in different known temperature environments under the condition of no external pressure, measuring the fluorescence intensity corresponding to each temperature dot, and fitting to obtain the linear relation between the temperature and the fluorescence intensity.
5. The fluid lubrication pressure and temperature monitoring method according to claim 1, wherein the perovskite quantum dots are CsPbBr 3 quantum dots.
6. A quantum sensor employing the fluid lubrication pressure and temperature monitoring method of any one of claims 1-5, comprising: The quantum dot lubricating oil comprises basic lubricating oil and perovskite quantum dots uniformly dispersed in the basic lubricating oil, and the perovskite quantum dots periodically enter a lubricating contact area and a non-contact area along with the lubricating oil in the running process of a lubricating system; the excitation light source is arranged outside the lubricating system and used for providing excitation light for perovskite quantum dots in the lubricating oil so as to generate fluorescent signals; The spectrum acquisition device is arranged outside the lubricating system and is used for acquiring fluorescent spectrum signals generated by the perovskite quantum dots under the action of excitation light in real time; The signal processing module is connected with the spectrum acquisition device and is used for extracting characteristic parameters from the acquired fluorescence spectrum signals and respectively acquiring pressure information and temperature information of the lubrication system according to the characteristic parameters; The time sequence control unit is connected with the spectrum acquisition device and is used for controlling the acquisition time of the spectrum acquisition device according to the movement period of the lubrication system, so that the spectrum acquisition device acquires fluorescent signals for pressure monitoring in a contact area and acquires fluorescent signals for temperature monitoring in a non-contact area.
7. The quantum sensor of claim 6, wherein the signal processing module comprises: The storage unit is used for storing a pre-established pressure-peak position calibration relation and a temperature-intensity calibration relation; and the calculating unit is used for substituting the collected fluorescence peak wavelength into the pressure-peak position calibration relation to calculate a pressure value, and substituting the collected fluorescence intensity into the temperature-intensity calibration relation to calculate a temperature value.
8. The quantum sensor of claim 6, wherein the lubrication system is a rolling bearing, a sliding bearing, or a gear pair.

Description

Fluid lubrication pressure and temperature monitoring method and quantum dot sensor Technical Field The invention relates to the technical field of fluid lubrication state monitoring, in particular to a fluid lubrication pressure and temperature monitoring method and a quantum dot sensor. Background In the operation process of mechanical equipment, the lubrication state is directly related to the operation reliability, energy efficiency and service life of the system. In particular, in key friction pairs such as rolling bearings, gear pairs, sliding bearings, etc., the pressure and temperature of the lubricating oil film are key parameters determining the oil film carrying capacity, viscosity change and tribological state. The internal pressure and temperature of the lubricating oil film are monitored accurately in real time, and the method has important significance for realizing the health management and predictive maintenance of equipment. At present, the monitoring means of the pressure and the temperature of a lubricating oil film mainly depend on contact sensing modes such as thermocouples, strain gauges, piezoelectric sensors and the like. The sensor is usually embedded or attached in a mechanical structure, so that the installation process is complex, wiring is difficult, the original lubricating structure and flow field distribution can be changed to a certain extent, and the actual working state of a lubricating interface is disturbed. In addition, the method is limited by space size, working environment and signal extraction mode, and is difficult to realize in-situ measurement of internal pressure and temperature of a lubricating oil film, and particularly has limited application in a lubricating system with high rotating speed and a closed structure. In recent years, optical sensing technology based on quantum dots has been attracting attention in complex and limited environmental monitoring due to its non-contact measurement, remote signal reading and good anti-electromagnetic interference capability. The quantum dot material has sensitive fluorescence response characteristics to external physical stimulus (such as temperature, pressure and the like), and provides possibility for developing a novel optical sensing method. However, the prior research of introducing quantum dots into lubricating oil systems has mainly focused on the aspects of antifriction and antiwear or lubricating property improvement. In addition, under the actual lubrication working condition, pressure and temperature are often acted on the luminescent material at the same time, and obvious coupling effect exists on the influence of the pressure and the temperature on the fluorescent signal, so that the contribution of different physical fields is difficult to directly distinguish by a single optical signal, and the difficulty of multi-parameter identification and quantitative characterization is further increased. Therefore, how to effectively distinguish pressure and temperature signals in a fluid lubrication medium is still a problem to be solved in the current optical lubrication state monitoring technology. Disclosure of Invention The invention aims to overcome the problems in the prior art and provides a fluid lubrication pressure and temperature monitoring method and a quantum dot sensor, which can realize effective differentiation of pressure and temperature signals in a fluid lubrication medium. The invention provides a fluid lubrication pressure and temperature monitoring method, which comprises the following steps: Uniformly dispersing perovskite quantum dots in basic lubricating oil, preparing quantum dot lubricating oil, and introducing the quantum dot lubricating oil into a lubricating system to be monitored; In the running process of the lubricating system, exciting quantum dots in lubricating oil and collecting fluorescence spectrum signals of the quantum dots in real time; The method comprises the steps of collecting fluorescence spectrum signals, extracting two characteristic parameters of fluorescence peak wavelength and fluorescence intensity from the collected fluorescence spectrum signals, converting the fluorescence peak wavelength collected by a contact area into pressure information of a lubrication contact area according to a pre-established pressure-peak position calibration relation, converting the fluorescence intensity collected by a non-contact area into temperature information of a lubrication oil film according to a pre-established temperature-intensity calibration relation, and distinguishing the fluorescence signals of the contact area and the non-contact area through a time dimension or a space dimension so as to realize in-situ distinguishing and monitoring of the pressure and the temperature in the lubrication system. Preferably, the contact area is an area where bearing contact is periodically formed between a moving part and a matching surface in the lubrication system, and the non-co