API 617标准中要求,离心压缩机产品(包括辅助设备)应确保其最短使用寿命为20年,不间断连续运转时间至少为5年。本文中的压缩机组高压缸转子在实际运行中发生了动力学失稳现象。通过分析,认为对于该机组的转子稳定性分析,应该考虑叶轮气...API 617标准中要求,离心压缩机产品(包括辅助设备)应确保其最短使用寿命为20年,不间断连续运转时间至少为5年。本文中的压缩机组高压缸转子在实际运行中发生了动力学失稳现象。通过分析,认为对于该机组的转子稳定性分析,应该考虑叶轮气动效应的影响,并发现考虑叶轮气动效应后的转子稳定性与实际运行情况一致,且不满足API 617的要求,为了改善该压缩机的转子稳定性,在叶轮口圈和平衡盘密封处添加阻旋栅,从分析结果看,该措施提高了转子的对数衰减率,满足API 617的要求。展开更多
A numerical investigation on the aerodynamic effects of impeller-diffuser axial misalignment in the low-flow-coefficient centrifugal compressor is conducted through three-dimensional CFD analysis.The results show that...A numerical investigation on the aerodynamic effects of impeller-diffuser axial misalignment in the low-flow-coefficient centrifugal compressor is conducted through three-dimensional CFD analysis.The results show that the flow,especially near the diffuser inlet,is influenced by the axial misalignment obviously.When the impeller offsets to one side,the pressure at diffuser inlet close to this side will descend,and the vortex in the cavity on the other side will partially enter the diffuser and then result in the back flow.The performances of the stage and its components also change with the impeller-diffuser axial misalignment.There exists an optimum offset making the efficiency maximum at a given operating point.Furthermore,the effect of impeller-diffuser axial misalignment on the axial thrust is pronounced.The axial thrust is nearly increased linearly with the increase of axial misalignment.The aerodynamic effects of impeller-diffuser axial misalignment in the low-flow-coefficient centrifugal compressor behaves more remarkably at the large flow rate.To alleviate the aerodynamic effects of impeller-diffuser misalignment,a rounding in the meridional plane at the diffuser inlet can be applied.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51236006)China Postdoctoral Science Foundation(Grant No.2012M521771)
文摘A numerical investigation on the aerodynamic effects of impeller-diffuser axial misalignment in the low-flow-coefficient centrifugal compressor is conducted through three-dimensional CFD analysis.The results show that the flow,especially near the diffuser inlet,is influenced by the axial misalignment obviously.When the impeller offsets to one side,the pressure at diffuser inlet close to this side will descend,and the vortex in the cavity on the other side will partially enter the diffuser and then result in the back flow.The performances of the stage and its components also change with the impeller-diffuser axial misalignment.There exists an optimum offset making the efficiency maximum at a given operating point.Furthermore,the effect of impeller-diffuser axial misalignment on the axial thrust is pronounced.The axial thrust is nearly increased linearly with the increase of axial misalignment.The aerodynamic effects of impeller-diffuser axial misalignment in the low-flow-coefficient centrifugal compressor behaves more remarkably at the large flow rate.To alleviate the aerodynamic effects of impeller-diffuser misalignment,a rounding in the meridional plane at the diffuser inlet can be applied.
