Simulation and Flow Analysis of the Hole Diaphragm Labyrinth Seal at Several Whirl Frequencies

Xiang Zhang,Xiuquan Qu,Guanghe Huo,Yinghou Jiao,Zhiqian Zhao

doi:10.3390/en15010379

Abstract

The seal is designed to reduce leakage and improve the efficiency of gas turbine machines, and is an important technology that needs to be studied in gas turbine design. A series of seals were proposed to try to achieve this goal. However, due to the complex fluid dynamic performance of the seal-rotor system, the seal structure can obtain both the best leakage performance and best rotordynamic performance. This paper presents a detailed flow analysis of the hole diaphragm labyrinth seal (HDLS) at several whirl frequencies and several rotation speeds. The pressure drop, velocity, turbulence kinetic energy and leakage performance of the HDLS were discussed by simulations. An interesting exponential–type relationship between rotation speeds and leakage flow at different whirl frequencies was observed by curve fitting technology. A reverse flow rate was proposed to describe such an unusual phenomenon. Such a relationship can be used to further establish the leakage model of the HDLS and other similar seals.

Highlights

Gas turbines and steam turbines, which can be both called “pearls on the crown of the manufacturing industry,” are two of the most complex machines in the current industry
Two flow loss coefficients used in the bulk-flow model [3] for the interlocking labyrinth seal (ILS) with clearances of 0.3 mm and 0.13 mm were proposed to predict the leakage performance more accurately, which can be used in predicting such seals
The analysis focused on pressure, velocity, turbulence kinetic energy, and leakage performance

Summary

Introduction

Gas turbines and steam turbines, which can be both called “pearls on the crown of the manufacturing industry,” are two of the most complex machines in the current industry. Different seal structures were proposed to reduce gas leakage to enhance the utilization rate of gas. One of these various seals is the labyrinth seal (LS). Leakage Performance The purpose of the seal is to reduce the leakage flflow,, wwhhiich ccaan iimprove both the wwork eefffificciieenncy ooff tthhee ttuurrbbiinnee aanndd ccoommpprreessssoorr. TThhee rreessuullttss sshhooww tthhaatt tthhee hhoollee ddiiaapphhrragm labyrinth seal presented in this paper obtains a 3.53% reduction in leakage performance, compared to that of the traditional LS, which can be described by the extra eddy dissipation effect in circumferential directions.

Leakage Performance

Findings

Conclusions