Aksijalna turbina za iskorištavanje energije uzgonskih sila u dimnjaku termoelektrane

master's thesis

• Title (english): Axial turbine for utilization of buoyancy force energy in chimney of thermal powerplant
• Author: Anja Horvat
• Mentor: Željko Tuković (mentor)
• Committee member: Darko Smoljan (predsjednik povjerenstva)
• Committee member: Tea Žakula (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2021-07-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

Provedena je analiza mogućnosti iskorištavanja energije uzgonskih sila koje se javljaju u dimnjaku termoelektrane primjenom cijevne aksijalne turbine, pri čemu se mehanički rad dobiva propuštanjem svježeg zraka iz okoline u dimnjak preko turbine. Nakon određivanja sastava produkata izgaranja za zadano plinovito gorivo, određeni su projektni parametri turbine provođenjem numeričkih simulacija strujanja smjese
vrućih dimnih plinova i svježeg zraka kroz dimnjak i cijevnu aksijalnu turbinu, gdje
je rotor turbine opisan modelom aktuatorskog diska.
Oblikovanje profila rotorske lopatice aksijalne turbine je provedeno primjenom
metodologije koja se temelji na numerički određenim aerodinamičkim karakteristikama
dvodimenzionalne turbinske rešetke uz korištenje uvjeta slobodnog vrtloga.
Postupak oblikovanja je implementiran u programskom jeziku Python pomoću kojeg
je povezan modul za definiranje geometrije rešetke s računalnim programom za
diskretizaciju prostorne domene cfMesh® i računalnim programom za provođenje
simulacija strujanja OpenFOAM®. Konstrukcija cijevne aksijalne turbine čiji se rotor
sastoji od novo-oblikovanih rotorskih lopatica provjerena je provođenjem numeričkih
simulacija trodimenzionalnog strujanja primjenom modela rotirajućeg koordinatnog
susatava. Rezultati simulacija pokazuju umjereno odstupanje snage turbine od
zadane snage što se može objasnit odstupanjem od pretpostavke dvodimenzionalnog
strujanja korištene prilikom oblikovanja rotorske lopatice.

Abstract (english)

Possibility of buoyancy force energy utilization in a chimney of a thermal powerplant using the axial-flow pipe turbine has been analysed. Mechanical work is obtained by
admitting the fresh air flow from the environment to the chimney via the turbine.
After determination of the flue gas composition for the given gas fuel, turbine design
parameters where determined by performing numerical simulations of the fresh air
and flue gas mixture flow through the chimney and the pipe turbine. In these
simulations the turbine rotor is represented by an actuator disk model.
Forming of the axial turbine rotor blade is carried out using methodology which
is based on numerically determined aerodynamics characteristics of two-dimensional
cascades and satisfaction of the free-vortex condition. This process is implemented
in the Python programming language which connects the module for defining the
geometry of the cascade with the meshing software cfMesh® and the fluid flow
simulation software OpenFOAM®.
The design of the axial-flow pipe turbine, whose rotor is composed of the
newly-formed rotor blades, is tested by carrying out the three-dimensional flow
simulation using the Multiple Reference Frames (MRF) model. Moderate difference
between turbine power and default power is noticed. This is due to deviation from
the two-dimensional flow assumption used in the rotor blade forming procedure.

• Keywords: RDF; aksijalna turbina; slobodni vrtloga; Ansys/Fluent; OpenFOAM; cfMesh; Rhino7; višestruki koordinatni sustav
• Keywords (english): CFD; axial turbine; free vortex; Ansys/Fluent; OpenFOAM; cfMesh; Rhino7; multiple reference frame
• Language: croatian
• URN:NBN: urn:nbn:hr:235:311129
• 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: 2021-07-13 18:40:56