24°球形管路接头低温密封性能研究

Study on cryogenic sealing performance of 24°orbicular pipe sealing joint

对24°球形密封管接头进行了计算分析,从理论与试验上分析24°球形管路接头的密封性能。首先利用界面渗透原理和A. Roth假设对界面微漏孔泄漏原因和理论模型进行了研究;其次利用双线性等向强化本构模型对球头密封面的弹塑性变形过程进行有限元分析;最后利用密封面微漏孔泄漏模型对常温和液氮环境下的球头密封特性进行了分析。研究结果表明:(1)24°球接头第一道密封面平均宽度0.296 mm,第二道密封面宽度0.389 mm;(2)24°球头密封面最大比压在573 MPa左右,第一道密封面平均比压381 MPa,第二道密封面平均比压290 MPa;(3)24°球头密封接头液氮环境下的理论泄漏率为4.0×10^(-6)Pa·s,与平均试验泄漏率5.1×10^(-)6Pa·s相比,误差为22%。

The calculation of 24°orbicular sealing pipe joint is carried out to analyze its sealing performance from theoretical and experimental perspectives.First,the principle of interface permeability and A.Roth’s hypothesis are applied to study the reason and theoretical model of interface micro leakage.Then,the elasto-plastic deformation process of the orbicular joint sealing surface is analyzed by using the bilinear isotropic hardening constitutive model.Finally,the sealing characteristics of the orbicular joint under room temperature and liquid nitrogen environment are analyzed by using the micro leakage rate model of the sealing surface.The results show that:(1)The average width of the first sealing surface of the 24°orbicular joint is 0.296 mm and that of the second is 0.389 mm.(2)The maximum specific pressure of the 24°orbicular sealing surfaces is about 573 MPa,the average specific pressure of the first and second sealing surfaces is 381 MPa and 290 MPa,respectively.(3)The theoretical leakage rate of 24°orbicular joint undera liquid nitrogen environment is 4.0×10^(-6) Pa·s,which has around 22%error compared with the average experimental leakage 5. 1 × 10 ^(- 6) Pa·s.