Research On Separating Metal Particles In Lubricating Oil In A Microfluidic Chip

Lubricating oil analysis,one of the most important methods to monitor the operation of ship machinery and equipment,can effectively diagnose and prevent all kinds of ship equipment failures.However,the existing oil detection means of marine power plant has disadvantages of low accuracy,a single detection,offline monitoring of oil.Recent years have witnessed the rapid development of microfluidic technology,which has advantages of a high degree of integration,rapid analysis and portable,and provides a new method for oil on-line detection.With the aid of the inertial separation and liquid pull effect,this paper designed a continuous separation and detection system for metal particles based on microfluidic chip,which realized the functions of the on-line continuous separation according to the size and type.Three research results and conclusions were obtained:(1)The numerical model of the metal particles under the action of the internal flow field of the micro-channel was established on the basis of analysis of the force and motion of the particles in the flow field.The flow field and the trajectories of the particles were simulated by COMSL.The effects of viscosity of lubricating oil,particle types,velocity and size on the separation efficiency were investigated by simulation.The results showed that the 15?m copper and aluminum mixed particles could be separated when the oil viscosity is 0.006 pa s and the inlet velocity is 0.08m/s.(2)Based on the theoretical research,a channel of microfluidic chip was designed and the microfluidic magnetic separation platform was set up.The separation of metal particles in the lubricating oil was completed.The control group was set up.,the 15?m copper and aluminum particles were through the separating channel at the speed of 0.08m/s respectively.It was found that the copper particles flow down to the copper particle collection channel smoothly,while the aluminum particles can flow upward towards the aluminum particle collecting channel.Finally,the separation of copper and aluminum was achieved by the 15 ?m copper and aluminum mixed particles through the separating channel.(3)A new method for separating metal particles in lubricating oil based on liquid pull effect was proposed.The separation system of metal particles with different sizes was designed and the separation of iron,copper and aluminum particles of 2.5?m,5?m and 10?m were respectively studied.The advancing rate of micro-injection pump was changed to control the gas-liquid interface running speed,and then the thickness of the liquid film and particle force situation were changed,and ultimately the different size particles were separated.