Validacija rješavača metodom harmonijske ravnoteže za simulacije pokretanja i zaustavljanja turbostrojeva

master's thesis

• Title (english): Validation of the harmonic balance solver for turbomachinery start-up and shut-down simulations
• Author: Luka Ćulić
• Mentor: Hrvoje Jasak (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2018-03-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Tema ovoga rada je istraživanje rada turbostrojeva u različitim režimima strujanja. Glavni uzroci promjenjivih režima rada su novosti u području proizvodnje električne energije. Vlade vodećih država svijeta potiču proizvodnju energije iz obnovljivih i održivih izvora energije, poput vjetra i solarne energije. Posljedica toga su oscilacije u električnoj mreži jer se električna energija ne proizvodi prema potrebi već ovisno o prirodnim uvjetima. U svrhu smanjivanja oscilacija električne mreže, najčešće se regulira snaga hidroelektrana. To je rezultiralo čestim promjenama opterećenja u turbinama, a za posljedicu ima kraći radni vijek. Da bi turbine prilagodili promjenama u režimu rada, potrebno je izračunati strujanje fluida tijekom cijelog perioda u kojem se mijenja režim strujanja. Simuliranje tako promjenjivih režima rada je skupo i neefikasno te je zbog toga je razvijen novi pristup metodom harmonijske ravnoteže za izračun tranzijentnih strujanja. U ovom radu prikazan je matematički model i metoda harmonijske ravnoteže koja će se koristiti za izračun tranzijentnih strujanja. Na kraju, eksperimentalni rezultati dostupni sa radionice Francis 99, bit će uspoređeni s dobivenim numeričkim rezultatima, kako bi se validirala metoda za izračun strujanja pri pokretanju i zatvaranju turbine.

Abstract (english)

This thesis investigates different turbomachinery flow regimes and transient behavior during regime change. One of the main reasons why turbomachinery is working in the different flow regimes are changes in the global electricity market. Global incitation for alternative, renewable and sustainable energy, such as wind and solar energy, has increased grid disruption because solar panel, wind turbines, etc., do not produce electricity according to demand. The volatility of the electric grid needs to be reduced and it is most often regulated by changing the flow regime in the hydro-power plant. This has resulted in frequent load variations in turbines and as a consequence shorter operating life. In order to adjust turbines to this new regime of work, fluid flow during whole transient period needs to be calculated and predicted. Simulating the complete transient period with available methods, is too expensive for industrial applications and therefore the Harmonic Balance method for transient flows is developed. In this thesis mathematical model and Harmonic Balance method will be presented. Furthermore, a novel approach to calculate changing flow regimes is presented. At the end, experimental results obtained as a part of the Francis 99 workshop will be compared with obtained numerical results in order to evaluate the method for turbine start-up and shut-down application.

• Keywords: Računalna dinamika fluida; foam-extend; metoda harmonijske ravnoteže; Francisova turbina; Tranzijentno strujanje; pokretanje turbine; zaustavljanje turbine
• Keywords (english): CFD; foam-extend; Harmonic Balance Method; Francis turbine; Transient flow; Start-up; Shut-down
• Language: croatian
• URN:NBN: urn:nbn:hr:235:279802
• 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 22:12:12