Performance Study Of Contact Mechanical Seal Based On Fractal Theory

The contact mechanical seal is the key sealing component in the chemical industry,aviation aircraft,shipbuilding industry,weapon industry and so on,and its sealing characteristics and friction characteristics of the end face have a great impact on the overall mechanical performance.Because of various factors,the service life of the contact mechanical seal is not the same,which can lead to the leakage of sealed media in the mechanical equipment in which the contact mechanical seal is used,especially that in the petrochemical industry.Most of the sealed media in the petrochemical industry are harmful,toxic,flammable or explosive,once a large number of the leakage happen,it is a major hazard.Therefore,it is of great significance to study the sealing characteristics and end-face friction characteristics of the contact mechanical seal.In this paper,the contact mechanical sealing is taken as the study object,and its sealing characteristics and end-face friction characteristics are analyzed,including leakage,wear,average temperature rise and thermal deformation.Then effects of main surface morphology parameters,material parameters and working condition parameters on the leakage,wear and average temperature and thermal deformation are analyzed,and the effect of wear and thermal deformation on leakage are discussed.The main contents of the paper are as follows:(1)Based on the domestic and foreign literatures on the sealing end-face leakage,wear,average temperature rise,thermal deformation and fractal theory of the contact mechanical seal,and a summary of the research status and development trend of the application of that is completed.The relevant literatures at home and abroad are analyzed in detail to find out their problems.Finally,combined with the research direction of our research group,the research content and research ideas are arranged in detail.(2)The fractal characteristics of the end face of the contact mechanical seal are analyzed,and the fractal model of the leakage of the contact mechanical seal is established.Based on fractal theory,the leakage problem of the contact mechanical seal is studied.Effects of fractal parameters,material parameters and working parameters on the leakage rate are analyzed.Finally,the calculated results of the present model are compared with the experimental results.(3)The fractal model of wear of the contact mechanical seal is established,and this model is used to modify the model of leakage of the contact mechanical seal.Based on the fractal theory,the wear problem of the contact mechanical seal is studied.Effects of fractal parameters,material parameters and working parameters on the wear quantity are analyzed.The calculated results of the model are compared with the previous experimental results.Finally,the wear fractal model is used to correct the fractal model of leakage,that is,the fractal model of leakage of the contact mechanical seal is established based on wear.(4)The fractal models of average temperature rise and thermal deformation of the contact mechanical seal are established,and this model is used to modify the fractal model of leakage of the contact mechanical seal established based on wear.Based on the fractal theory,the average temperature rise and thermal characteristics of the contact mechanical seal are studied.Effects of fractal parameters and working parameters on the average temperature rise and thermal deformation are analyzed.The fractal model of thermal deformation is used to correct the fractal models of leakage of the contact mechanical seal with wear in the previous part,that is,the fractal model of leakage of the contact mechanical seal is established based on wear and thermal deformation.(5)The leakage measurement experiment of M7N-40 contact mechanical seal is carried out.The surface topography of the static ring of M7N-40 contact mechanical seal is measured.A mechanical seal test bench is set up,and the leakage rate is measured experimentally.The calculated data based on the fractal model of leakage of the contact mechanical seal in consideration of wear and thermal deformation are compared with the previous experimental data.