大型500 kV变压器主密封法兰系统受力分析

利用有限元分析软件ABAQUS对油浸式变压器的主密封界面的螺栓、垫片、法兰系统进行建模,分析预紧状态下法兰螺栓受力及变形情况,探讨接触应力随橡胶垫片压缩率、流体压力、橡胶垫片硬度的变化规律。结果表明:在螺栓预紧载荷作用下,法兰偏转使螺栓受力不均,箱沿连接处为法兰最易损坏位置,可在箱沿与箱体处加额外刚性固定来增加强度;随着压缩率与流体压力的增大,橡胶垫片的接触应力和von Mises应力均增大;橡胶垫片硬度越大,相同流体压力下的接触应力和von Mises应力也越大,因此当密封界面承受较大流体压力时,应选用硬度大的橡胶垫片。

Stress Analysis of Main Sealing Flange System of Large 500 kV Transformer

The bolt,gasket and flange system of the main sealing interface of oil immersed transformer was modeled by the finite element analysis software ABAQUS.The force and deformation of flange bolts under preload condition was analyzed,and the change rule of contact stress with compression ratio of rubber gasket,fluid pressure and hardness of rubber gasket was discussed.The results show that under the action of bolt pre tightening load,the flange deflection causes uneven stress on the bolts,and the box along the joint is the most vulnerable position of the flange.Additional rigid fixation can be added at the box edge and box body to increase the strength.The maximum contact stress and von Mises stress are increased with the increasing of compression ratioand fluid pressure.Under the same fluid pressure,the greater the hardness of rubber gasket is,the greater the contact stress and von Mises stress are.Therefore,the rubber gasket with higher hardness should be selected when the sealing interface is under large fluid pressure.