天然气掺氢对管线压缩机轴端干气密封动力学特性的影响  

Influence of Hydrogen Blending in Natural Gas on the Dynamic Characteristics of Shaft-End Dry Gas Seals in Pipeline Compressors

作　　者：夏永波 欧阳欣 程磊 李志刚[1] 李军[1] XIA Yongbo;OUYANG Xin;CHENG Lei;LI Zhigang;LI Jun(Institute of Turbomachinery,Xi’an Jiaotong University,Xi’an 710049,China;Science and Technology Research Institute,National Oil and Natural Gas Pipeline Network Group Company Limited,Langfang,Hebei 065000,China)

机构地区：[1]西安交通大学叶轮机械研究所,西安710049 [2]国家石油天然气管网集团有限公司科学技术研究总院分公司,河北廊坊065000

出　　处：《西安交通大学学报》2024年第12期186-196,共11页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(52176042)。

摘　　要：为探究天然气掺氢对管线压缩机轴端干气密封动力学特性的影响,提出了干气密封动力学特性的三自由度多频扰动非定常计算流体力学摄动数值预测方法,通过实验和数值结果验证了方法的可靠性。采用该方法研究了10种扰动频率、4种掺氢比和3种进口压力对干气密封动力学特性系数的影响规律,结果表明:所提方法能准确预测干气密封受轴向和角向多频率扰动时的动力学特性系数;随着扰动频率的增大,气膜轴向阻尼和角向直接阻尼呈抛物线趋势减小,表明气膜在高频扰动下易失稳;随着掺氢比的增加,气膜轴向刚度和角向直接刚度分别减小了7.81%~12.19%、6.66%~14.05%,轴向阻尼和角向直接阻尼变化较小(<5%),表明天然气掺氢降低了气膜抵抗外界轴向和角向扰动的能力,但对气膜恢复平衡稳定的能力影响较小;增加进口压力会提高各动力学特性系数,有利于干气密封形成稳定气膜。研究可为掺氢条件下天然气管线压缩机轴端干气密封的可靠设计和安全稳定运行提供参考。To explore the impact of hydrogen blending in natural gas on the dynamic characteristics of shaft-end dry gas seals(DGS)in pipeline compressors,a three-degree-of-freedom multi-frequency perturbation unsteady computational fluid dynamics perturbation numerical prediction method for dynamic characteristics of DGS is proposed.The method’s reliability is verified through experimental and numerical results.Using this method,the effects of ten disturbance frequencies,four hydrogen blending ratios,and three inlet pressures on the dynamic characteristic coefficient of DGS are examined.The results demonstrate that the proposed method accurately predicts the dynamic characteristic coefficients of DGS under axial and angular multi-frequency perturbations.As the disturbance frequency increases,the axial gas film damping and angular direct damping decrease in a parabolic manner,indicating the gas film’s susceptibility to instability under high-frequency perturbations.With an escalation in hydrogen blending ratio,the axial gas film stiffness and angular direct stiffness diminish by 7.81%to 12.19%and 6.66%to 14.05%,respectively,while the axial damping and angular direct damping exhibit minimal changes(<5%).This suggests that hydrogen blending in natural gas reduces the gas film’s capacity to withstand external axial and angular disturbances,but has a relatively minor impact on its ability to restore balance and stability.Furthermore,increasing the inlet pressure enhances all dynamic characteristic coefficients,which is beneficial for the formation of a stable gas film in DGS.This study provides valuable insights for the reliable design and safe operation of shaft-end DGS in natural gas pipeline compressors under hydrogen blending conditions.

关 键 词：干气密封 天然气掺氢 多频扰动 动力学特性 

分 类 号：TH136[机械工程—机械制造及自动化]