Numerička analiza učinkovitosti HULA brtve

master's thesis

• Title (english): Numerical analysis of HULA seal performance
• Author: Daniel Wolff
• Mentor: Željko Tuković (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2017-01-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Ovaj rad bavi se brtvljenjem velikih sučelja između gornjeg i donjeg dijela unutarnjeg kućišta komore izgaranja u silo izvedbi. Provedena je analiza učinkovitosti hlađenja hula brtve koja bi zamijenila staru belt brtvu. Hula brtva je fleksibilna prstenasta brtva koja se koristi za kompenzaciju pomaka između dvije cilindrične komponente, a da pritom pruža učinkovitu izvedbu brtvljenja. Plinska turbina na koju će se ugraditi hula brtva je starija plinska turbina s komorom izgaranja u silo izvedbi koja koristi belt brtvu za brtvljenje sučelja između gornjeg i donjeg dijela unutarnjeg kućišta komore izgaranja. Glavni razlog za odabir ove plinske turbine je veliko trošenje i troškovi popravka same belt brtve i sučelja između gornjeg i donjeg dijela unutarnjeg kućišta komore izgaranja u odnosu na druge slične plinske turbine. U okviru ovoga rada računalna dinamika fluida korištena je za provjeru učinkovitosti hula brtve i uspoređena je sa učinkovitosti belt brtve. Za gornji i donji dio unutarnjeg kućišta komore izgaranja te za belt brtvu korišteni su već postojeći geometrijski modeli dok je model hula brtve izrađen prema patentu hula brtve. Iz tih modela sklopljena su dva slučaja, onaj sa belt brtvom i onaj sa hula brtvom. Za numeričku analizu korišten je periodički isječak iz cijele geometrije oba slučaja radi smanjenja vremena računanja. Numerička analiza uključuje volumen kroz koji struji fluid te stijenku unutarnjeg kućišta kako bi se ispitala interakcija između njih odnosno da bi se saznalo kako hlađenje zrakom utječe na toplinske uvijete komponenti. Dobiveni rezultati sadrže polja tlakova, brzina i temperatura, te strujnice kako bi se što bolje opisali toplinski uvjeti i strujanje fluida. Na temelju rezultata izveden je zaključak da hula brtva u odnosu na belt brtvu nije dovoljno učinkovita odnosno ne osigurava potrebno hlađenje kućišta komore izgaranja. Kao preporuka za povećanje učinkovitosti navedene su
promjene na samoj hula brtvi.

Abstract (english)

This thesis deals with large-scale cylindrical interface sealing between the hot gas path components of silo combustion chamber. Implementation of hula seal for replacing old belt seal will be checked in order to minimize the amount of cooling and leakage air, without negative impact on the lifetime of the components. Hula seal is annular flexible spring finger seal used to compensate misalignment between co-annular parts, while providing effective sealing performance. It is circumferential metal seal that is slotted in the axial direction and contoured to be spring-loaded between inner and outer diameter of the matching parts that experience relative axial motion. Long term successful implementation of the hula seal for sealing of stationary interfaces for industrial and aero gas turbine engines confirms benefits like improved lifetime of the hot gas parts, reduction of manufacture costs and on-site assembly time. The target engine type is older gas turbine that currently uses belt seal as seal for cylindrical interface between the hot gas path components of silo combustion chamber. Main reason of choosing this engine is the highest wear impact and costs of the belt seal compared to other engines. In scope of this thesis computational fluid dynamics method is used to verify the sealing performance of the hula seal and compare it with belt seal performance. Models of belt seal, combustion inner liner and hot gas casing that are used already existed, while hula seal model was designed by descriptions from patent. From this models, assembly of two cases were made, one for belt seal case and one for hula seal case. Periodic models were created from assembly models to reduce mesh generation and computational time. Numerical analysis solved conjugate heat transfer problem which means that along fluid flow, heat transfer interaction between fluid and solid was solved as well. Result which shows fluid flow and thermal condition of fluid and solid are presented. Based on result it is concluded that performance of hula seal model used in this thesis are not good enough. Compared to belt seal hula seal cooling performances are worse. Suggestions for improving hula seal performance were given.

• Keywords: Hula brtva; numerička analiza; plinska turbina; komora izgaranja; prijelaz topline
• Keywords (english): Hula seal; Gas turbine; Computational fluid dynamics; Numerical analysis; Combustion chamber; Conjugate heat transfer
• Language: croatian
• URN:NBN: urn:nbn:hr:235:731727
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 18:29:39