On the Development of a Pressure Actuated Leaf Seal for Turbomachinery Applications
On the Development of a Pressure Actuated Leaf Seal for Turbomachinery Applications
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用于涡轮机械应用的压力驱动叶片密封件的开发
DOI：
10.1115/gt2019-90991
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Pedraza-Valle E
中科院分区：
文献类型：
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作者：
Pedraza-Valle E
在燃气涡轮机中，减少高压区域和低压区域之间的泄漏的密封件对于改进性能至关重要。发动机启动和停机瞬态过程中，由于热和装配不对中以及转子动力学振动，涡轮轴密封件的旋转和非旋转部件之间会发生损坏性摩擦。这些摩擦导致密封泄漏增加，并因此导致整体涡轮机效率和寿命降低。膜压驱动叶片密封（FRPALS）是一种正在开发的非接触式柔性密封，它能适应各种间隙而不产生摩擦，同时保持低泄漏。该钻机具有直径为254 mm的转子，最大表面速度为200 m/s。可实现高达3.5 bar的压降。在零转速下的初始测试的结果，提出了在反向的FRPALS。叶片的打开和关闭平移已经使用涡流位移探头测量，目标是密封件的可移动部件。密封间隙已被证明在一定范围的应用压降下保持恒定，这表明密封的稳定运行，尽管导致在1.5 bar下与转子接触。质量流泄漏测量也证明了FRPALS的密封性能。它们显示了密封件在设计修改以保持更均匀的膜厚度的情况下的膜承载潜力。润滑的稳态雷诺方程已被用于预测沿密封间隙沿着的压力。的预测已与压力测量从位于间隙流体薄膜中的传感器。
In gas turbines, seals that reduce the leakage between high and low pressure regions are critical for improved performance. Damaging rubs between the rotating and non-rotating parts of turbomachinery shaft seals occur due to thermal and assembly misalignments, and rotordynamic vibration during engine start-up and shut-down transients. These rubs lead to increased seal leakage and hence to reduced overall turbine efficiency and life span. The Film Riding Pressure Actuated Leaf Seal (FRPALS) is a non-contacting compliant seal under development to adapt to varying clearances without rubbing, while maintaining low leakage.This paper presents the measurements of the FRPALS in a test rig specifically designed to test novel shaft seals for turbomachinery. The rig features a 254 mm diameter rotor with a maximum surface speed of 200 m/s. Pressure drops of up to 3.5 bar can be achieved. The results of initial testing at zero rotational speed are presented for the FRPALS in a reverse orientation. The opening and closing translations of the leaves have been measured using eddy current displacement probes targeting the movable parts of the seal. The seal clearance has been shown to remain constant for a range of applied pressure drops, which indicates the stable operation of the seal, though resulting in contact with the rotor at 1.5 bar. Mass flow leakage measurements have also demonstrated the sealing performance of the FRPALS. They show the potential of the seal to film ride subject to design modifications to maintain a more uniform film thickness. The steady-state Reynolds equation for lubrication has been used to predict the pressure along the seal clearance. The predictions have been compared with pressure measurements from a transducer located in the clearance fluid thin film.