突起を有した階段型のラビリンスシールの性能評価

抄録

As the sealing device for rotary machines such as turbo compressors, labyrinth seals are commonly using as a non-contact seal. Among other things, Step-seals (Labyrinth seal whose shaft has a staircase shape) are used in general because of good assembling and high sealing performance. In recent years, labyrinth seals have been required that further reduction of leakage along with increasing pressure of turbo machineries and for higher efficiency. In this paper, the high performance seal with easy assembling have been proposed which just have protrusions on the stepped parts in the step seal. It is suggested that sealing characteristics of proposed seal was conducted by CFD analysis and experiments. First, optimal proposal structure was shown by study of changing step height and protrusions height on the steps. It became clear that proposal seals have effect of reducing leakage up to over 30 % compared to general step seals. Experiments for confirming performance of the proposed seal were carried out and proved to be effective at any pressure. As a feature of the proposal seal, it was confirmed that this seal exerted high performance with only small protrusions, even if it has a large clearance or a large displacement in the axial direction.