Leakage Characteristic Identification of Labyrinth Seals on Reciprocating Piston through Transient Simulations

Abstract

In the reciprocating labyrinth piston compressor, the characteristic of the internal leakage is crucial for the leakage management and performance improvement of the compressor. However, most of the published studies investigated the rotor-stator system, and those who study the reciprocating piston-cylinder system basically focus on the effects of the geometrical parameters. These conclusions could not directly be applied to predict the real-time leakage flow rate through the labyrinth seal because of the fast reciprocating motion of the piston, which will cause continually pressure change in two compression chambers, and then the pressure fluctuation will affect the flow through the labyrinth seal. A transient simulation model employing the multiscale dynamic mesh, which considers the effect of the reciprocating motion of the piston in the cylinder, is established to identify the characteristics of the internal leakage. This model was verified by a specially designed compressor, and the influence of various parameters was analyzed in detail. The sealing performance decreased linearly with the increase in the pressure ratio, and higher pressure inlet leads to higher leakage flow under the same pressure ratio. The labyrinth seal performance positively correlated to the increase of the rotational speed. Leakage characteristics of five working mediums were carried out, and the results indicated that the relative leakage decreased with an increase in the relative molecular mass. From this study, the realistic internal leakage flow rate under different operating parameters in the reciprocating labyrinth piston compressor could be predicated.

Inteligência Artificial Para Identificar O Uso De Máscara Na Prevenção Da Covid-19

“…Most of the research related to labyrinth seals study the rotor-stator system, that is, for rotating elements, and those that study the cylinder-piston system basically focus on the effects of geometric parameters, (WANG et al, 2019). (CANGIOLI et al, 2017), and(VERMES, 1961) explored the labyrinth seal flow calculation method.…”

“…Currently the main research methods for labyrinth leaks are the analysis of thermodynamic theory, numerical analysis method, leak measurements, flow visualization method. Other studies investigated the mechanism in rotating machines and combined the CFD method, and theoretical analysis to study the flow pattern within the labyrinth seal and analyze the effect of the structural arrangement and the pressure relationship on the sealing efficiency, (WANG et al, 2019).…”

“…The problem that will be addressed here is the lubrication and sealing, and therefore an effective sealing. (SCHALLER; DARVISHSEFAT; SCHLÜCKER, 2018) and (WANG et al, 2019) stated that oil-free lubrication carries the gas completely dry and avoids gas contamination due to oil. Also, if PCRs are equipped with a non-contact seal it would have no wear and almost unlimited service life.…”

A pneumatic piston-released rapid compression machine for chemical kinetics studies at elevated pressure and low to intermediate temperatures

“…In practice, the hydraulic seal is subjected to dynamic force from fast-moving shaft rods. There is, however, a distribution of the contact pressure around the sealing contact and this contact pressure depends on the geometry of the sealing edge [45]. During operation, hydraulic seals experience continuous wears, subjected to dynamic stresses by the shaft which not only reduces service life, but the sealing edge geometry also changes gradually overtime of operation, the variation in sealing edge geometry eventually leads to room for small oil leaks to enter the reaction chamber, thus hindering the fidelity of experimental data.…”