Research On Measurement Technology Of Oil-gas Two-phase Flow In Recirculaculating System Of Lubricating Oil

The aeroengine recirculating system of lubricating oil collects lubricating oil for lubrication and cooling to ensure the normal circulation of lubricating oil in the aeroengine system.Due to the high-speed rotation and stirring of the bearing,the lubricating oil and air are mixed with each other,and complex oil-gas two-phase flow is formed in the recirculating pipe of lubricating oil.It is of great practical significance to investigate the working state of the oil-gas two-phase flow parameters in the recirculating pipe of lubricating oil.However,due to the complexity and changeability of oil-gas two-phase flow in the recirculating pipe of lubricating oil,there are many problems to be solved in parameter detection.In this thesis,a capacitance-tomography sensor was designed for the oil-gas two-phase flow in the recirculating pipe of lubricating oil,and the flow pattern identification and void fraction measurement of the oil-gas two-phase flow in the horizontal pipeline were realized by combining the principal component analysis method,K-means clustering algorithm and principal component regression method.The main work and contributions of this thesis are as follows:1.An 8-electrode ECT(Electrical Capacitance Tomography)sensor suitable for the recirculating pipe of lubricating oil was designed,which includes the insulated pipe,the electrode array and the shielding can,realizing the acquisition of Capacitance signal reflecting the distribution of oil and gas two-phase media in the pipeline.2.Based on the 8-electrode ECT sensor,combined with principal component analysis,K-means clustering algorithm and principal component regression method,flow pattern identification model and voidage measurement model were established and the flow pattern identification and void fraction measurement of oil-gas two-phase flow in horizontal pipeline were realized.The feasibility of the established models were verified.3.The experimental equipment of oil-gas two-phase flow was designed and built,and the experimental research of flow pattern and void fraction of oil-gas two-phase flow was carried out.The results show that the accuracy of flow pattern identification is more than 95%,and the maximum absolute error of cross section void fraction is less than 10%.