热变形对高压干气密封结构件的影响及材料的选用

Influence of thermal deformation on high pressure dry gas seal structure and the selection of materials

某合成气压缩机组存在的主要问题是干气密封泄漏较大、产量损失大,影响机组稳定运行,需要对干气密封进行改造。分析了密封机理、影响密封性能的关键因素、结构、材料等,分别对动环、静环和动静环配对进行了温度及热应变计算,结果表明:环体最高温度出现在端面内侧,最低温度出现在环体外环面上;密封环材料的热传导率对密封环的热变形有影响;动静环配对正常工作时,端面热变形会导致从外径向内径形成一个收敛形间隙。根据热应变的影响来进一步优化动环槽型,与热变形位置进行合理匹配,目的是提高密封高压状态下的稳定性,从而保证机组的稳定运行。

The stable operation of a syngas compressor unit is affected mainly due to the problems of dry gas seal leakage and large loss of yield;so that the dry gas seal needs to be transformed.The seal mechanism,key factors effecting the seal performance,seal structure and materials are analyzed,and the temperature and thermal deformation calculation is figured up for rotating seal ring,stationary seal ring and their pairing.The results show that the maximum temperature appears in the inner side of end face of ring,while the minimum temperature appears in the outer surface of ring.The pyroconductivity of seal ring materials has effect on the thermal deformation of seal ring,and the thermal deformation of seal ring will result in a convergence gap from outer diameter to inner diameter during the normal pairing of rotating seal ring and stationary seal ring.In order to increase the stability of dry gas seal under high pressure and ensure the normal operation of compressor unit,the groove profile of rotating seal ring needs to be optimized based on the thermal deformation to match the position of thermal deformation.