Performance Analysis of Ultra-low Temperature Variseal Based on Percolation Theory
The Variseal can compensate the compression deviation and has good high-speed surface dynamic performance. However,since the material of casing mainly uses plastics with large thermal expansion coefficients,it often leads to a decrease in sealing performance and even a large leakage in ultra-low temperature environments such as liquid hydrogen. Based on the percolation theory,considering the roughness of the sealing surface,this paper established the thermo-solid coupling analysis model of ultra-low temperature rotating variseal,analyzed the influence of different casing materials on the friction and leakage of variseal in ultra-low temperature environment. The friction and leakage in the liguid hydrogen environment are used as the evaluation indexes of the sealing performance. The outer diameter,the thickness of the sealing lip and the inner diameter are the main parameters. The influence of each casing structural parameter on the sealing performance is analyzed. The optimal model size parameters under the given requirements are obtained and verified by experiments. The results showed that under the medium pressure of 5MPa in liquid hydrogen environment,the friction force of polytrifluorochlor oethylene ( F3 ) casing material with the same structural parameters is 2.26 times that of polytetrafluor oethylene ( F4 ),and the leakage is 0.867 times. When other structures remain unchanged,the larger the outer diameter of the variseal,the larger the friction force and the smaller the leakage. The thicker the thickness of the variseal,the larger the friction and leakage of the variseal. After the optimization of the variseal structural parameters,the leakage rate decreased by 63.30％ at the medium pressure of 5MPa.
VarisealUltra-low TemperatureSealing PerformancePolytrifluorochlor OethylenePolytetrafluor OethylenePercolation Theory
万方数据
维普
